Schwartz hadn't practiced since injuring his hip at Fan Fest on Aug. 7.
"That's a tough one," Rivera said. "We hoped that he would react positively to the treatment. He's been out for a long time, and we have to move forward with this season unfortunately. Hopefully he can get it taken care of and be ready to go (next year)."
Rivera did not specifically address whether Schwartz will need surgery.
"It was a situation where he wasn't getting better," Rivera said.
The decision to put Barnidge on injured reserve was not a surprise because he will miss 12 weeks because of a fractured ankle. Pike, a sixth-round pick in 2010 out of Cincinnati, had elbow surgery last week on his right throwing arm after missing most of training camp. Gettis and Williams each tore an ACL during training camp but weren't eligible for IR until Tuesday.
Copyright 2011 by The Associated Press