The SMU secondary already was thin following the knee surgery that ended cornerback Sterling Moore's season a game early, but one of his replacements also sat out Saturday's practice. Junior cornerback Chris Castro watched from the sideline with his left arm in a sling after separating his shoulder during Friday's practice.
Castro suffered the injury while covering freshman wide receiver Steve Nelson on a deep pass route.
"I landed on the back of my shoulder, and I couldn't move my arm," Castro said. "I knew something was wrong, and I think I kind of went into shock."
The injury is not expected to keep Castro from playing in the Bell Helicopter Armed Forces Bowl Dec. 30 at Gerald J. Ford Stadium.
"It's just a matter of the swelling and the pain," Castro said, "but I'll definitely be back for the bowl game. I'm shooting for Wednesday to get back (on the practice field).
"Mostly, they want me to get my range of motion back. Once I do, then it's just a matter of putting up with the pain. Last night, I couldn't even get my jacket off, and had a hard time getting comfortable when I went to sleep. But it's already feeling better. They want me to be careful with it, but I'll be ready."