Going just by the facts we know, this is a player who prior to 23-24 season was depressed to the point he already told his GM during the summer he is not going to come back for the season - ends up changing his mind, suffers several injuries including a broken cavicle (I think it was?) and a bad concussion, playing only 18 games that season before entering the PAP, missing the rest of the season. Gets traded to MTL for peanuts, suffers a severe knee injury in preseason, which initially was thought to be season ending, on a knee that has been operated 4 times prior, including a major surgery after an injury that already put his career in jeopardy years ago.
Now give him the benefit of the doubt and assume this is hardest working guy in the league and ask yourself, are you surprised he's not currently playing anywhere close to his best level? Now be a realist and assume he probably didn't keep his conditioning at a level where it needs to be for an top NHL player through the times he was seriously considering quitting hockey, and then suffers a knee injury during preseason - a preseason he probably sorely needed just to get his skating back to acceptable and ask yourself are you surprised?