Watch the replay - he doesn't grab his head in reaction to the laceration (which was undoubtedly painful) he falls like a man knocked out and lays motionless for a bit before the trainers can get there. Knee in side of head = concussion in majority of cases. I would be very surprised if he didn't have a concussion. He's in the protocol. You don't go through that if there's not evidence he sustained one.
I think the concussion has the potential to keep him out longer than the laceration. Hopefully he's back this week or next.