ALLEN PARK -- Rodney Austin is an unknown commodity.

He hails from small-school Elon. He never flashed his best stuff there because of injury. And he's never played a snap of offense since signing with the Detroit Lions after going undrafted two years ago.

But Austin, listed at 6-foot-4 and 311 pounds, is strong as a bull -- multiple players have told MLive they believe he is the team's strongest player -- and that strength continues to intrigue teams.

That includes the Titans, who tried to sign Austin off Detroit's practice squad last year. And that includes the Lions, who countered by finally signing Austin to their 53-man roster despite having no immediate plans to play him.

But that could be changing.

With left guard Rob Sims limited Wednesday during OTAs -- as he also was during minicamp last month -- it was Austin who was repping with the first unit in his place.

"Just good to be out here," Austin said. "To hell where my position is, I just like taking reps. Wherever I can get them, I'm going to take them."

[Related: Rodney Austin opens up on his past in a wide-ranging Q&A]

Austin is saying the right things, but it is notable he was used as the primary backup to Sims.

Larry Warford was a rock at right guard last year, where he played every snap and didn't allow a sack during his exemplary rookie season. And the Lions spent a third-round pick to make Travis Swanson their center of the future.

That means the only interior spot with any kind of uncertainty is left guard. And it appears he's winning the job as the top interior reserve, though Swanson could also compete for that role.

"It's good working with the first group, especially next to Dom and Riley. Helps to get the timing down and getting a better feel for the plays." Austin said.

Austin's confidence is soaring after the Lions gave him a roster spot late last season. He touched an NFL field for the first time in the season finale against Minnesota -- albeit on special teams -- and now he's hoping for more in 2014.

"Just got to keep grinding," he said. "I went home and trained this offseason, came back here and trained some more. Came back with a little more confidence. Just knowing that I got there last year helps me this year.

"Now I'm doing what I'm supposed to do and staying in this playbook. Got to get back on the 53-man roster, baby."