Of COURSE its a concussion. He already had the test during the intermission and DIDN'T pass or else he would be out there.
Remember last season? He missed a a bunch of games due to a concussion, even though they never admitted it, we all knew it was from the Lucic hit.
“@AGrossRecord: Rick Nash, of course, missed four games last season due to a concussion after a high hit from the Bruin's Milan Lucic.”