Rams strong safety James Butler suffered a knee injury during practice Friday, and it has been diagnosed as a sprained medial collateral ligament, the *St. Louis Post-Dispatch* reported Saturday.
"It's going to keep (Butler) out a little while," Rams coach Steve Spagnuolo said Saturday. "I don't want to classify it as significant. We'll take it day to day, but I think it'll be an extended injury."
Butler, 27, played his first four NFL seasons with the New York Giants, the final two with Spagnuolo as defensive coordinator. Butler joined the Rams last season, when Spagnuolo became coach.
Craig Dahl is filling in with the first-team defense during Butler's absence.