Frank Gore just puts his head down and runs. He's not known for being flashy, not known for talking a lot, not known for showing off. But it's worked.

For 15 years, Gore has been doing that in the NFL. On Sunday, he surpassed Barry Sanders in rushing yards making him the number three all-time leading rusher in league history with 15,289 yards. And he did it on the same set of legs that endured two ACL tears in college.

"I'm blessed, I'm happy," Gore said. "For me it was tough to get to the NFL. I've been doubted my whole career. I tore my two ACLs and a lot of people said you will be here only two or three years and now in my year 15 I'm still having fun and still making plays, still helping a team win games."

Gore was drafted 65th overall in the 2005 NFL Draft to the San Francisco 49ers. Some said it was a reach for the injury-riddled running back out of Miami. In his first year he appeared in 14 games, starting once in Week 12. He played in two more games that season, rushing for two touchdowns and 176 yards. It was the last time he wasn't a starter.

For the next 14 seasons, Gore has started every game he's played in. Five times he made the pro bowl, including a stretch from 2011-13 where he made it there every season.

"He just comes in and works and doesn't say anything," quarterback Josh Allen said. "He puts his head down and doesn't care about stats and numbers or this and that. He wants to help his team win football games and at 36 years old and how hard he's playing, how hard he is, how physical, I mean it's unbelievable. But I can see why. Just the amount of work that he puts in and the preparation that goes into it."

It was a long path to the Bills for Gore. He spent 10 years in San Francisco before bouncing around to Indianapolis, Miami and now Buffalo, his third team in as many years. Despite bouncing around he's led every single team in rushing yards he's been on.

Gore was recruited to Buffalo by ex-Bills running back LeSean McCoy. The two were going to share a backfield in the home stadium of two of the greatest running backs in NFL history OJ Simpson and Thurman Thomas.

But McCoy ended up being cut by Buffalo before the two could take the field together this season and Gore has taken to mentoring another young running back from Florida, Devin Singletary.

"It's like having a little brother," Gore said. "Ever since he's been drafted, I've had him in my hip pocket. He listens to everything I say. Great kid, real natural. There's going to be a chance for him to be real big in this league."

"He kind of reminded me of myself man, very natural, great feet, great eyes," Gore said.

On the same day that Gore crossed his threshold, Singletary was able to surpass 100 yards rushing for the first time in his career.

Singletary wasn't sure he was going to hit 100 yards; Gore was assured he was reaching the 46 he needed to pass Sanders.

Allen told him last night that they were getting it today and after a 27-yard run in the third quarter, running backs coach Kelly Skipper told him the same.

"My running back coach came up to me and said, 'hey we're getting it today'" Gore said. "I just want to say thank you to Skip for keeping me up these past couple of weeks man. He's been keeping my spirits up and letting me know I'm a big part of this team."

Gore has taken less snaps this year than he's used to, but his impact has been felt throughout the locker room and coaching staff. It's still surreal for Allen to hand off to the man he owned the jersey of as a kid. Head coach Sean McDermott said it was an honor to gift him a game ball on Sunday.

"To witness what we've all witnessed out here we should all be grateful for being able to see that," McDermott said. "Those names that are up there are legendary names and Frank is right with those guys. To be number three is an incredible testament to his work ethic, his mental toughness and proving people wrong."