David DeCastro tears MCL; ACL OK

Pittsburgh Steelers right guard David DeCastro dislocated his knee cap, tore his medial collateral ligament and suffered some damage to his patellar tendon. But his anterior cruciate ligament is intact, according to sources.

The team is unsure if the 2012 first-round draft pick will be able to return this season after receiving the results of his MRI on Sunday.

DeCastro was hurt while pass blocking as Pittsburgh faced third-and-8 at its 6-yard line on its second possession in Saturday night's preseason game against the Buffalo Bills. DeCastro's right leg twisted beneath him after being bowled over by defensive tackle Marcell Dareus.

DeCastro, the 24th overall selection out of Stanford who started Saturday's game over Ramon Foster, lay in the end zone for a few minutes as trainers worked on his leg. He briefly got up on his own, but was unable to put any weight on his right leg. He took a few hops before trainers stopped him and called for a cart.

Information from The Associated Press was used in this report.