Marcus Sherels rarely shows his emotions and limits his conversations to only a few words at a time. He might be the most unassuming player in the NFL.

The Vikings punt returner/cornerback just quietly goes about his business, never one to draw attention to himself, a perpetual underdog who believes every day could be his last in the NFL.

This training camp is no different. Sherels is on the roster bubble again, his usual spot. He can't afford to have a bad game or bad practice, because bubble players have little margin for error in their fight to make the 53-man roster.

Sherels is dealing with something far more serious and personal right now, as well. His father died on the eve of the preseason opener, and his funeral will be Saturday. Sherels' family thinks he should miss the Vikings preseason game Sunday at San Francisco so that he can grieve and attempt to gain some closure. Marcus said he hasn't decided whether he will catch a flight after the funeral and play in the third preseason game.

"It's been tough, but I've had a lot of support from my teammates and coaches and organization," Sherels said. "Everyone has been remarkable to me, and they've really helped me up."

His father, Ben, died of cancer at age 60 after a lengthy battle. Ben had decided to stop chemotherapy treatments because his cancer had spread.

Marcus spent a lot of time with his father in his final few months. The Vikings even gave him permission to skip meetings in the evenings in Mankato so that he could drive to Hastings after morning practice to be with his father.

Their final visit came the day before the preseason opener in Houston. His father died shortly after Marcus left. He decided to play the following night.

"I knew he would want me to play, and I knew I needed to take my mind off it and come out with the guys," he said.

Marcus and his older brother Mike lived with their mother and stepfather as kids. Mike, a former Gophers linebacker, described the relationship with their dad as complicated. They weren't particularly close in their early years, but their relationship grew and strengthened in the past 10 years. Marcus became especially close to his father.

Mike, an assistant coach with the Gophers, wishes his brother had time to process everything that's happened.

"Mentally, he's a tough kid," Mike said. "It's really stressful fighting for a roster spot and knowing that without his full attention and full athletic capability, he probably doesn't make the team. He's one that always has to be 100 percent and this happens, and you can see he's distracted. I feel for him in that regard. At the same time, I know he's a fighter."

Marcus had a few rough moments against Buffalo on Friday night, but he refuses to use his personal situation as an excuse.

"You can't let it affect you," he said. "This is my job and when I'm here, it's football. You can't worry about anything else."

Sherels has played three NFL seasons, which is three more than anyone expected when he showed up at Winter Park for a rookie tryout. He impressed everyone that weekend and just refused to go away.

He's extremely reliable as a punt returner and shifty in tight quarters. He scored on a 77-yard punt return against Detroit last season and can return kicks.

Sherels' primary competition at punt returner and fifth cornerback is Bobby Felder, who helped his cause against the Bills. Felder downed two punts inside the 5-yard line and returned three punts for 62 yards.

Sherels knows he needs a strong finish to preseason to secure his spot again. His brother thinks getting closure this weekend will help clear his mind.

"There's not a lot of time to deal with some of these emotions," Mike said. "Some people have the luxury of taking a few days off work or a week off and just let the grieving process go. During two-a-days, you don't have that option. You've just got to keep going."

Chip Scoggins chip.scoggins@startribune.com