Cardinals rookie WR Marvin Harrison Jr. suffers concussion

GREEN BAY, Wis. -- Arizona Cardinals wide receiver Marvin Harrison Jr . left Sunday's 34-13 loss to the Green Bay Packers in the second quarter with a concussion and did not return.

After the game, Cardinals coach Jonathan Gannon wasn't sure how severe Harrison's concussion was.

Quarterback Kyler Murray , however, said losing Harrison was "unfortunate."

"For me, it's just continue to play my game, continue to execute what [offensive coordinator] Drew [Petzing] calls. But, obviously, you don't want to lose your guy out there.

"But we got to, obviously, keep playing the game."

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.

Not having Harrison on the field for more than half the game left Arizona without one of its primary playmakers, which changed the complexion of the offense.

"It's a big part of our offense," running back Emari Demercado said. "That takes away a big threat. But we just got to keep operating. There's things we can control and things we can't. That's something we can't, so we just got to keep playing. [Wide receiver] Mike [Wilson] made plays, [tight end] Trey [McBride ] made plays. Everybody's just got to step up and make plays."