FLAGSTAFF - Cardinals receiver Early Doucet suffered a sprained left shoulder while making a diving grab of a pass thrown by Matt Leinart on Monday morning.
The Cardinals said Doucet will undergo an MRI exam.
Doucet, a third-round pick in 2008, struggled through his rookie season, hindered by a hamstring injury suffered at training camp.
He is competing to climb the depth chart enough to be active on Sundays. It's a difficult task because the Cardinals have four established receivers ahead of Doucet: Larry Fitzgerald, Anquan Boldin, Steve Breaston and Jerheme Urban.