Perhaps the biggest disappointment of Steelers training camp has been the struggles of first-round pick David DeCastro.

Considered the best guard prospect to come out of college in a decade, DeCastro has failed to beat out Ramon Foster, who went undrafted three years ago, for the starting right guard spot.

Quarterback Ben Roethlisberger asked DeCastro whether he was having more difficulty with the mental or physical part of the game. "He said, ‘The mental part I got. The physical is a lot tougher. These guys are really good,'" Roethlisberger told the Beaver County Times.

DeCastro still might end up starting at right guard in Thursday's preseason opener at Philadelphia because left guard Willie Colon is dealing with an ankle injury. That would move Foster from right to left guard, opening the right guard spot for DeCastro.

Foster made it clear that he isn't conceding the starting job to DeCastro.

"You don't want to just passively give away your starting role," Foster told the Pittsburgh Post-Gazette. "This is a world championship team, you want to be a guy starting on that team. We're both going to get better no matter who wins the job. We'll just handle that at the end of camp. Is there a sense of urgency? Definitely. I think it's there for Dave, too."