COLUMBIA — His big brother left home in 2005, heading up the road to play running back at Clemson. But back in Georgia, Mike Davis kept watching James. And with every spectacular run James made, Mike started hoping, as little brothers do, that he could one day mimic him.

James was an instant star for the Tigers, making good on his ranking as the nation’s sixth-best running back recruit in his class, according to Rivals.com. Mike, who is seven years younger, attended games at Clemson, and upon returning home, he began to rethink his football identity. He had always played running back and safety, but favored safety.

“I liked the fact that my brother was scoring touchdowns,” Mike said.

“So I was like, ‘Hey, let me try running back. Maybe I’ll be good at this.’ That’s the reason why I played it. When I got to high school, I played both positions, but scoring touchdowns, it felt so much better. So I was like, ‘I’ll just stay on the offensive side.’ ”

He never turned back. He arrived at South Carolina this summer as Rivals’ seventh-best running back recruit in the country, and the highest-rated overall recruit in USC’s Class of 2012. He didn’t plan on playing, what with Marcus Lattimore, Kenny Miles, Brandon Wilds and Shon Carson ahead of him.

Then, in the preseason, Wilds sprained an ankle and Carson broke his wrist. The coaches decided to redshirt Wilds, who played as a true freshman last season, which elevated Davis to third on the depth chart. He had just 19 carries all season until Oct. 27, when Lattimore suffered a season-ending knee injury against Tennessee.

The rest of the season, which ends Jan. 1 in the Outback Bowl against Michigan, would serve as an extended preview of 2013 for Davis. Miles is a fifth-year senior and Lattimore, a junior, turned pro. So during spring practices, Davis could beat Wilds and Carson for the starting job.

“Spring is going to be huge, because who is going to be that No. 1 guy?” said running backs coach Everette Sands. “That’s going to be found out in the spring. Everybody brings a little something different to the table. Blocking on pass (protection) is going to be big.”

That’s where Davis made the most progress this season, when the help of his older brother. Davis said he was “all over the place” with pass protection during preseason practices. Studying film with Lattimore and Miles helped. So did playing more after Lattimore’s injury. In the three games since, he has 28 carries for 118 yards and a touchdown, including 12 carries for 43 yards in the regular season finale win at Clemson, which James did not attend.

Miles remains USC’s top option. In the past three games, he has 57 carries for 209 yards and a touchdown. Carson, a redshirt freshman, hasn’t played all season, but he returned to practice during Clemson week and will play in the bowl, Sands said.

Still, Davis’ experience — and he will get more in the bowl — is letting him grow faster than he would have if he redshirted, partly because he can discuss his performances with James.

“The thing we talk about the most is pass protection,” Mike said. “The running is coming easy. He always tells me he thinks I have better vision than him.”

James figured it would unfold like this for his little brother, that he would carry the ball just fine, but struggle with handling the sheer number of blitzes he would face in college, much more than he needed to understand in high school. James told Mike as much before the season. Of course, Mike’s blocking issues are typical for a young running back.

“One of the words I like to use is he’s got some ‘juice’ to him,” Sands said. “He has the ability to make some people miss. He’s also powerful and usually low to the ground. When the ball is in his hands, he can definitely do some things. There’s no doubt in my mind about that.”

Even though Davis has worked through his shortcomings by playing, Sands didn’t have to state the obvious: Some doubts remain about Davis’ reliability when the ball isn’t in his hands. In the New Year, beginning with the Outback Bowl, Davis can erase them.