Mac Brennan had a job to do. That’s what helped him fight off the fatigue and hold back the nausea.

Even in the throes of leukemia, when he was bedridden and aching all over, the child would do his duty: He would watch the film of that day’s Utah football practice, sent to him by coach Kyle Whittingham. And in return, he would send back detailed, written notes: what was being done well, what had been done poorly, and who was loafing.

“He had a lot of critiques,” Whittingham said with a laugh. “It was classic.”

Utah’s “assistant running backs coach” never got a dime for his labors and observations, but the tasks occupied many of his empty hours over 31/2 years of cancer treatment, and he gained a role on a team that he loved.

Over the last decade, the Brennan family has become ingrained in University of Utah athletics: Mac’s father, Kyle Brennan, is the school’s deputy athletic director, while his mother, Beth, is the academic coordinator for the football program. Now 11 years old, Mac is the middle of three brothers (Patrick, 14, and Murphy, 9) who have been rabid Utes fans for as long as they can remember.

But Mac’s cancer diagnosis in 2013 changed everything for the family, as cancer does, and it changed their relationship with the university. Utah became not just the place where the Brennans worked and the team they rooted for.

In their hour of deepest need, it became their family.

“I don’t know how else we could have pulled it off,” Kyle Brennan said. “It was amazing.”

Chris Detrick | The Salt Lake Tribune Utah Utes quaterback Cooper Bateman (18) hands off to Utah Utes Jordan Howard (26) during a scrimmage at Rice-Eccles Stadium Friday March 31, 2017.

The world crumbles

Mac has a round, almost cherubic face that over the last 31/2 years has waxed and waned with a cycle of chemo, steroids and hospital stays.

Before all that, however, he was a little guy.

“He was such a squirt,” Beth said, laughing. “But he was fearless.”

When Mac was 7, he darted around competitors two years older than him on the gridiron and the basketball court. He never shied from playing with his older brother Patrick’s friends.

That’s why it was so strange to the Brennans in December 2013, when Mac complained to his parents that his knees ached, or that he wanted to sleep rather than play sports. It rang alarm bells in their heads when, during a basketball game, Mac waved to be subbed out — something he never did. The next morning, Kyle was dressing his son when he saw mysterious bumps under the boy’s arms.

They took him to the doctor that day, figuring he was having a reaction to a flu shot, or his egg allergy was flaring up. To their horror and shock, the doctor ordered a blood test that showed a clear result: Mac had cancer.

“I was sure they were crazy,” Beth said. “It didn’t seem possible.”

The next few days blur together in the family’s memory. They rushed to Primary Children’s Hospital, where Mac underwent surgery to insert a chemotherapy port under his collarbone. He had never seen so many needles, so many tubes that were going into his body.

He remembers a doctor telling him he had leukemia — a curable form of cancer, but requiring a lengthy treatment cycle. For a 7-year-old, that is impossible information to process.

“I thought I was going to be in the hospital for one day,” he said. “I asked my parents if I was going to be OK, and they said yes. But then I asked, ‘If I’m going to be OK, why are you crying?’ ”

Mac learned a lot about cancer over the next few years. Cancer is taking more than a dozen pills every day — pills that will counterintuitively make you better by making you feel bad. It’s eating hospital food until you’re sick of it. It’s your hair falling out and having strangers stare at you. It’s steroids that make you gain weight.

Cancer is waiting in a room during chemo treatments, watching movies to make the time pass — and sometimes being too tired to do even that.

The most defining part of cancer for Mac during his first year of treatment, which doctors told the Brennans would be the hardest, was the isolation. Sports, his traditional refuge, were out because he was so tired. He couldn’t go to school, which doctors viewed as a petri dish of threats to Mac’s chemo-weakened immune system. He saw friends his age once a month at most.

Mac felt he wasn’t allowed to be a kid.

“I remember telling them,” he said, “ ‘you’re destroying my world.’ ”

Chris Detrick | The Salt Lake Tribune Utah Utes fans watch during a scrimmage at Rice-Eccles Stadium Saturday March 25, 2017.

Making it work

When Mac was diagnosed with leukemia, there were many moments when the Brennans felt like their world was collapsing.

But more times than not, they found support as they tried to hold everything together.

That reached back to the very early days, when Beth didn’t leave the hospital for almost two weeks as Mac underwent his first round of chemo. She doesn’t remember much from those days — they have a tendency to blur together — but one of those first evenings, she and Kyle walked out of a grim meeting with a doctor to find Kathy Hill, wife of athletic director Chris Hill, bearing a bag of fast food for them.

“That just meant so much,” Kyle said.

There were many other gestures from the athletic department. Early on, as Patrick and Murphy struggled to understand their brother’s illness, Chris Hill took them for walks to get away from the hospital, and even to a men’s basketball game to take their mind off the turmoil at home.

The cancer diagnosis had also caught the Brennans in the middle of a big transition — while Mac was in the hospital, they had finished inspections and closed on a house. With one of their sons seriously ill, the prospect of moving seemed like an impossible task. But when it came time to go to the new house — a necessary change, as it turned out, given that Mac needed his own bathroom — people within the athletic department paid for a moving service to help the family.

“It was this huge load off our minds,” Beth said. “We had no idea how we were going to deal with everything.”

Even with the move finished, the Brennans could foresee a future full of scheduling conflicts. Beth designated herself as Mac’s primary caretaker, maintaining a notebook of doctor instructions and coordinating his medications. He would have to go in for chemo treatments as well, and both Kyle and Beth wanted to be with him.

Beth fretted over what those time commitments would mean for her role as academic adviser for the football team. She approached her boss, football coach Kyle Whittingham, and said she would have to quit.

Not a chance, Whittingham replied.

“She’s been remarkable for us — there hasn’t been anything she hasn’t been able to handle,” he said. “We told her if there was any way she could make it work, we would make it work.”

Many days, Beth would work from home, taking phone calls from coaches and players as usual. Over the years Mac was ill, Utah football’s academic progress rate rose from a 970 multiyear APR in 2013 to a 983 mark in 2016 — an all-time high for the football program.

Hill also made allowances for Kyle to leave the office to be with Mac for chemo treatments. He remained busy, balancing projects such as the multimillion-dollar basketball practice facility, which opened in 2015, with his son’s appointments.

“In our department, we want people to work hard,” Hill said. “But we want people take care of home base as well.”

Chris Detrick | The Salt Lake Tribune Utah Utes forward David Collette (13) is helped off of the court after falling during the game at the Huntsman Center Saturday March 4, 2017.

Joining the team

There was another issue that was tougher to tackle. Out of school, it was hard for the then-8-year-old to fill his hours without friends or sports.

“I was cut off from the world,” he said. “I needed something to do.”

Kyle started bringing Mac to work more, and letting him shoot around in the gym. It was there that Mac crossed paths with then-basketball assistant Phil Cullen, who invited him to practices.

Mac became a fixture around the Runnin’ Utes, sitting in during shootarounds and practice sessions, and giving coach Larry Krystkowiak his thoughts afterward. He became close to players in the program, including Brandon Taylor and Jordan Loveridge.

That 2013-14 season was particularly tough for the Utes, who were also dealing with trainer Trevor Jameson battling cancer (he’s since punched it into remission).

“Mac provided us with a lot of perspective, and I think our players did a nice job of involving him in our practices,” Krystkowiak said. “It was a win-win.”

The football team had a similar affinity for Mac, who started hanging around practices almost every day. Whittingham appointed him as running backs coach Dennis Erickson’s assistant — a role that the kid coach took very seriously.

Far from a star-struck fan, Mac would analyze each running back’s performance, unafraid to give a player an earful if he thought that he was dogging it in practice. He talked with Erickson, six decades his senior, about the merits of Devontae Booker versus Bubba Poole, or if he saw something a particular back had done well that day.

“Oh, he always tells me exactly what he thinks,” Erickson said. “He didn’t hold back. We had quite a dialogue about football.”

To this day, he’s close with many former and current athletes, texting basketball player Kyle Kuzma about his summer league performances, or asking running back Troy McCormick which sneakers he should wear on a given day.

“They all see me as just a person,” he said. “We’re all just good friends.”

Where the heart is

It was last summer when the family was preparing for yet another huge change.

Kyle Brennan accepted the athletic director position at Montana State, which seemed like a sensible move for a rising star in the field. But for Mac, who still had another year of treatment remaining, it raised some uncertainty.

“My first question was, ‘Do they have a good hospital?’ ” he said.

Bozeman, Mont., it turns out, does have a good cancer hospital. But there were many other questions. Would it be a good time to relocate Mac in the middle of his treatment? Would Beth, who had become indispensable for the Utah football program, be able to find a job there?

Then there was a larger sacrifice to make: giving up their adopted home.

Neither Beth nor Kyle is from Utah, and neither expected to stay long after moving to Salt Lake City in 2008. But through the years, their experience in the state had far exceeded their expectations.

They had friends who drove Patrick and Murphy to sports when they were in the hospital with Mac. They had friends who dropped off dinner or clean laundry. Both Kyle and Beth like to joke that hundreds of people know their garage door code — their door was always open, and in their hour of need, people in the community streamed in to help.

“When people go through that with you through that period of time, it’s like family,” Beth said. “It’s like, ‘What a crazy group.’ They were there for us.”

Within a week of accepting the Montana State job, Kyle changed his mind and decided to stay at Utah. While there were many factors that went into the decision, the community that they had built in the athletic department — the ones who were keeping their world from crumbling — was never far from their minds.

Mac’s assessment: “I think my dad made the right decision.”

As it turned out, the decision to stay at Utah was fortuitous. A month later in August, doctors discovered Mac was suffering from pancreatitis as a result of his chemotherapy. He had several long stays in the hospital the following fall as his body struggled with his treatments. It was exceptionally painful — Mac describes a piercing sensation in his gut — but the family had no choice but to soldier through it.

In retrospect, it would’ve been tough to change caregivers. The Brennans now see Kyle’s decision, which understandably was not well-received at Montana State, as working out the way it should have.

“It’s hard to be brave enough to change directions when needed,” Beth said. “It was a really complex decision, but I think Kyle made the right choice in the end.”

The Utes feel that way as well. Whittingham got a phone call from the Brennans not long after Kyle changed course. When he learned both Brennans would remain in their current roles with the Utes, the football coach exhaled.

“It was like keeping two 5-star recruits,” he said. “Three, if you count Mac.”

The end

There’s a bell at Primary Children’s Hospital in the cancer ward, and it’s tradition for a patient who has beaten cancer to ring it at the end of his or her treatment.

That wasn’t how Mac wanted to celebrate. While beating cancer can inspire hope for some patients, he is also sensitive to how it can be a little crushing for others to reflect on how far they have left to go.

But Mac did mark the end of 31/2 long years with something equally cathartic. When he wrapped up his medication this spring, the family took the empty, worn-out pillbox that had run his life, coated it in gasoline and burned it.

“That was fun,” Mac said. “It was like, ‘Goodbye.’ I felt so much better.”

Not everything is immediate when cancer treatment ends. Mac has grown back his hair, which is neatly trimmed. Every day, he gets a little faster and can be a little closer to the athlete he once was, but he’s not there yet — not close, he complains.

In many ways, Mac has been forever changed by his experience. His parents say they notice he’s more attuned to others’ emotions and more compassionate. He seems to navigate relationships with others with ease, and he frequently texts his many friends he’s made over the years — football and basketball players included.

“He has a social life that I don’t fully understand,” Beth said of her now-11-year-old. “He’s just really good at that stuff.”

Mac now imagines a life where he will help others the way they helped him. He’s been shaped by a community in Utah that was there to support his family at every turn.

The Brennans give back, too. When Krystkowiak was diagnosed with thyroid cancer last year, he kept an extremely close circle, hiding his health trouble even from many players. But one of the people who knew was Kyle Brennan.

“I had some real heartfelt conversations with Kyle,” Krystkowiak said. “It’s great to have people in your foxhole when you’re going through that.”

Beth said she’s always seen work and life as factors that intermingle and flow together, but maybe not more so than the last few years. The family was able to handle Mac’s treatment and their work life, and it might not have been possible if they didn’t work in the Utah athletic department.

Others who were close to the Brennans feel the same way.

“It was very, very special,” said Erickson, who has since retired but stays in touch with the Brennans. “I’ve never been in a situation like that in all my years where that happened. It is unique, but it’s the atmosphere created in that athletic department all the time, starting with Chris Hill.”

Many of those people were at Mac’s end-of-treatment party at Deer Valley in June, including members of the football staff and basketball staff, players, administrators, sports information personnel, trainers and other Utes. They gathered around as Mac spoke.

“I went through life sick, thinking, ‘This is all I can be. This is all I can do,’ ” he told them. “But now I think I need to be just like you guys.”

Twitter: @kylegoon