I know we're still waiting for his MRI and it obviously will play a huge part in this decision but, seeing the schedule, it seems to me sitting out game 1 to get extended rest before game 2 could be a better option to have him healthy (or as healthy as he can be) for the rest of the series : he would not play from Sunday to Thursday (Game 2) whereas playing Game 1 would have him playing two days only after Game 7, on Monday.
His teammates could prepare for game 1 without him, which is obviously will be harder since we're already way short on players, but at least they'd be mentally ready. Thoughts ?