SANTA CLARA Asked if he's always been a patient person, if a mellow gene had been passed down by his parents, Marcus Lattimore laughed.
No, it's quite the opposite, the 49ers running back said this week.
Patience was very much an acquired trait. And it didn't come easily.
"It's something where I had to really train myself to be that way," he said. "It took awhile. It's something I had to grow into. Because it's not there naturally."
For the past six months, Lattimore had been rehabilitating alongside fellow injured draft picks Tank Carradine and Quinton Dial. On Tuesday, Carradine, Dial and two other rehab partners, wide receiver Mario Manningham and cornerback Eric Wright, joined the rest of the 49ers at practice for the first time this season.
Rehab is slow and repetitive. It's "Groundhog Day" at the gym. Every day is leg lifts, leg curls and leg extensions. There are enough sessions on an exercise bike to make you feel like you've pedaled the Tour de France 20 times.
What makes it more tortuous is that just a few yards away, the rest of the team practices and prepares for the upcoming game. An injured player must feel like a child banished to his bedroom, face pressed against the window, while the other kids play outside.
Players cope with their time on Monotony Island with humor and camaraderie.
Lattimore said you can't help but crack jokes and bond with the guy stuck on the exercise cycle next to you.
"We all relate to what we've all been through and what we're going through in the rehab," he said. "Those have become my brothers. I mean, we jelled. And there's nothing that can take that away."
While his mates have escaped the island, Lattimore remains stranded.
That's where the patience comes in. Lattimore, 21, is the third-youngest player on the 49ers' roster but comes off as one of the most mature.
He said he had to be. Later this month is the one-year anniversary of the grisly knee injury that left players on two teams Lattimore's South Carolina squad and visiting Tennessee kneeling in concern as he was carted off the field.
Lattimore had come back from an ACL tear suffered the previous year. By last October, he had scored 11 touchdowns, was considered by many the top runner in the nation and was a certain first-round draft pick. However, the injury was so severe his right kneecap was dislocated and three ligaments were torn that his NFL dreams seemed to be dashed in an instant.
Instead, he worked steadily and slowly over the ensuing months to prove to NFL teams he was draft-worthy. The 49ers were convinced, using a late, fourth-round pick on him in April.
Coach Jim Harbaugh said during the draft the plan was to have Lattimore rehabilitate the entire 2013 season so he can come back as strong as ever in 2014. That's still the plan. But there's a carrot in front of Lattimore as he toils through rehab every day, even if it's not a very juicy one.
The player who set a school record for touchdowns and was the Southeastern Conference's Freshman of the Year in 2010 said he'd merely like to put on shoulder pads again and join his teammates in practice. That's a possibility.
Players like Lattimore who are on the non-football injury list are allowed a three-week window to practice with their teams between Weeks 6 and 11. At that point, they either are elevated to the active roster or shut down for the rest of the season.
"I still might get a chance to practice this year, and it might be soon," Lattimore said. "I look forward to it. I'll be head over heels when that happens."
Until then, he'll continue his familiar circuit through the weight room and the long rides on the stationary bike. You won't hear him whine, moan or flash jealous looks at his former rehab buddies.
"When those days come and I say, 'I'm sick of doing this, I'm tired of doing this,' I just say to myself, 'I'm blessed to even be here right now,' " Lattimore said. "I'm in the NFL. And there's no reason to complain."
Read Matthew Barrows' blogs at www.sacbee.com/sf49ers and listen for his reports Tuesdays on ESPN Radio 1320.