DEARBORN -- Reggie Bush won a Heisman Trophy at USC and was picked second in the 2006 draft.

Theo Riddick was picked 199th last year.

And yet Bush insists that Riddick, entering his second season with the Detroit Lions, is ahead of where he was at that age and is primed for a breakout season in 2014.

"I think he's going to be a sleeper for us," Bush said. "He's going to be a huge part of our offense and what we're able to do this year. He's hard to guard one-on-one, so that's going to be good for us to have an extra piece of the puzzle."

The Lions are implementing a new offensive system under first-year coordinator Joe Lombardi, and that scheme is expected to strongly resemble the one used in New Orleans, where Lombardi has been an offensive assistant the past seven years.

And New Orleans likes to use an array of tailbacks.

That is expected to be featured here as well, which could mean more opportunities for Bush, Joique Bell and the third tailback.

Riddick is battling Mikel Leshoure for that role, and though both could see time, it appears Riddick has emerged as the favored option because of his improved skill-set in the passing game.

He'll be a man to watch when Detroit opens its three-day mandatory minicamp Tuesday in Allen Park.

"I have (seen) a big growth. He's always been a really good natural runner, but I feel like his route running, his pass-catching skills, have really improved a lot," Bush said.

Riddick, plucked in the sixth round out of Notre Dame, surprised some last year by edging out Leshoure -- then Detroit's reigning rushing leader -- for the third tailback role.

He became a core special teams player, and was very good there, but was used sparingly on offense. He caught four passes for 26 yards, and also carried the ball nine times for 25 yards and one touchdown.

But Bush maintains that Riddick is an advanced natural runner, particularly as compared to him.

"When I got to my rookie year, I was trying to outrun everybody to the sideline. It took me a few years to develop that natural, running-between-the-tackles ability," Bush said. "The NFL and college are so different. So for me, it took a couple years to get to that point. But for him, he already has that natural ability. So he's very, very advanced for a rookie -- or now a second year.

"I'm looking forward to seeing some big things out of him this year."

Paired with his offseason gains -- particularly in the pass game -- it seems Riddick has positioned himself solidly as the third tailback. And in this offense, that could be a significant role.

"I'm sure you'll see him used a lot in the passing game this year, and in the run game," Bush said.