One of the more intriguing training camp battles for the San Francisco 49ers is the one for the third running back job. The current frontrunners for that spot are Raheem Mostert and second-year running back Joe Williams.

The 49ers made Williams a fourth-round draft pick last year. However, a slow start and then a minor ankle injury kept him out of the regular season after he landed on injured reserve.

All reports out of Santa Clara have indicated that Williams has made tremendous strides since his rookie offseason. Not only is he making more plays during practices, but he also looks bigger and seems more motivated.

One person who is excited to see Williams hit the football field during Thursday night's exhibition opener against the Dallas Cowboys is the man who fought hard to draft the running back out of Utah.

"I'm excited to watch him play out on the field," head coach Kyle Shanahan told reporters on Tuesday. "I'm a lot more excited now than I was last year because of what he's shown in practice. I think you guys have seen it yourselves. I know you guys have heard us talk about it. He's come a long way in a year, and he's given himself a chance to be a good running back. We'll see how it looks on Thursday."

Given last year's setback, Shanahan admits to second-guessing the Williams pick. After all, general manager John Lynch was initially against the selection, and it took some persuading by Shanahan and running backs coach Bobby Turner — and a phone call to Williams — to change his mind.

"I do believe in Joe's ability and his talent," Shanahan said last week. "That's why we wanted him here. But, lots of guys have ability and talent in this league. It's hard, and it's not for everyone. You don't fall into playing in the NFL. You've got to be talented, and it's got to mean a lot to you.

"I think it does to Joe. But, I think it's taken him time to see the difference and the urgency that it takes to succeed at this level."

That sense of urgency from Williams has been apparent during training camp. He appears locked in and ready to fight for every yard on the practice field.

"Joe wasn't quite as ready last year, and that does make you wonder because you can't succeed if you don't have that mindset. But, I've seen it this year. I saw it in the way he worked, and I feel that he fixed his body, got a lot more muscle, and got in better shape."