I am a physician here in the USA. I saw the incident with Laf.
I could not slow it down more than they already did, and I could not rewind, but it looked like a MCL sprain or tear (and if it's a tear it's basically both).
Unfortunately, the ACL is also a secondary stabilizer to stresses of valgus and helps anchor the knee joint during any rotation movements (limiter).
I don't want everyone to just think it's the worst, though. You just don't know until the MR is done. I've seen people in extreme pain, only to find out they have a sprain/strain injury.
I say all of this as he was holding his knee.
This could also be an ankle injury- but again, from the replay that I could not replay myself, his ankle seemed to be the lever not the item that was injured. His skate got stuck at the pads it seemed, but the ankle didn't itself seem to move much, but the knee instead.
Again, I could be wrong here.