Cardinals rookie WR Marvin Harrison Jr. suffers concussion

GREEN BAY, Wis. -- Arizona Cardinals wide receiver Marvin Harrison Jr. was ruled out of Sunday's 34-13 loss to the  Green Bay Packers with a concussion.

The fourth overall pick went down with 6:28 left in the second quarter when his head collided with the thigh of Packers linebacker Isaiah McDuffie after a pass to Harrison fell incomplete.

Harrison was helped off the field by Cardinals trainers and, after getting evaluated in the blue injury tent on the sideline, left the field and was escorted to the locker room by a team of Arizona trainers and doctors.

He was ruled out shortly after the second half began.

Harrison did not have a catch on two targets Sunday.