Palmer suffered a left arm injury during Sunday's contest against the Rams in London, Darren Urban of the Cardinals' official site reports.

EDGE Analysis

After taking a hit on a second-quarter interception, Palmer was looked at by the team's medical staff before going to the locker room. As he left the field, he was holding up his left arm while swinging his right arm normally, according to Josh Weinfuss of ESPN.com. If Palmer is unable to return, he'll end the day 10-of-18 passing for 122 yards and the pick. Meanwhile, Drew Stanton took over direction of the offense.