"Running back Michael Bush awoke a fullback Monday, and he didn't even know it.

"Yeah, that's all I'm going to say about that," Bush said after Monday's practice, which was done behind closed gates in Alameda for the first time since training camp started.

Bush's body language did the talking for him.

When met by reporters in the locker room, he dropped his chin into his chest and let out a deep sigh. Consider this the latest wild turn in a 16-month pro career full of them.

The Raiders drafted Bush with the first pick of the fourth round in 2007. A Heisman hopeful at Louisville, he was touted as a future star once his broken leg recovered.

Instead, he spent half the season on the physically unable to perform list and the other half on injured reserve, even though Bush said his leg was healthy and ready to play.

Bush was made a short-yardage specialist in the offseason. When fullback Oren O'Neal was lost for the season with a knee injury Saturday, Bush was moved into his spot.

"I've always been a team player," Bush ended up saying. "So, it's one of those things. You just suck it up, go about your business and try to have some fun with it."

Bush certainly has the size to be a fullback. He's 6-foot-1 and 245 pounds with above-average tailback speed and dependable hands.

His ability to catch screen passes could secure playing time while he learns the position.

"Mike is a very mature guy, so if he has to line up there, he will," fullback Justin Griffith said. "He'll get it done."

Coach Lane Kiffin did not discuss the position change during his news conference."