Could be no specific event and entirely based on the fact he's a tall guy and spending all that time hunched over is hard. Being longer/taller puts extra strain on joints. I don't know what his off-ice workout routine is. I'd consider moving away from free weights if he's using them. Move to plyometrics, pilates, yoga, etc. Reduce high impact exercise in favour of low impact resistance training and core strengthening. Kovalev was ahead of the curve in this regard. He'd moved to this form of training before joining the Canadiens.
It's stuff he and the team will have to keep an eye on.
The more concerning injury for me is the wrist. Not knowing which wrist it is, even once heeled it could severely hamper his shot.
