The Nemesis
Semper Tyrannus
He had a surgery that spring, might be not too successful if another one is needed now though.
This might also explain why they waited until now. If the surgery he got in Russia didn't fix everything, the Sharks might've told him to wait to get another one until after he was signed so that it would be under the direction and care of the Sharks and not his KHL club so that they could keep a closer eye on everything and have more direct oversight of the process and his rehab.