The San Diego Chargers may be forced to turn to rookie Chris Watt at center for Sunday’s game against the Oakland Raiders with Doug Legursky placed on injured reserve Tuesday with a knee injury.

Legursky was filling in for Rich Ohrnberger (back), who he was filling in for Nick Hardwick (neck).

Watt, a third-round pick from Notre Dame, saw action at right guard and center during Sunday’s victory over the New York Jets.

“I just have to get in there and step-up,” Watt said. “I’ve worked on it in practice all week. I worked on it in the preseason.”

The Chargers also signed center Trevor Robinson off the Cincinnati Bengals’ practice squad and re-signed veteran running back Ronnie Brown. Linebacker Kevin Reddick was waived.

Robinson is a third-year player also out of Notre Dame who signed with the Bengals as an undrafted rookie in 2012 and appeared in six games last season.