Was very solid as a rookie in the AHL and decent enough in the NHL as a 21 years old.
Definitely didn't appreciate being sent down and did a lot worse than his AHL rookie season.
Didn't play much in the Covid season and then was taken by the Kraken.
That woke him up for the AHL, but he never took a step forward in his ability to play more than replacement level defense in the NHL.
I don't think it is fair to say that he didn't show the ability to play in the NHL when he was never really given a chance. He literally was given less than 6 minutes in preseason games before being waived the last couple of years. Seattle then used him strictly as injury replacement only, but their D has been ridiculously healthy since they came into the league. The games that he did play he was actually not bad at all.
He plays a safe, smart game. He breaks the puck out well and skates decently. There is no dynamic offensive side to his game, so he is what he is, but teams could do a lot worse having him playing a defensive role as a 6/7 guy that won't really hurt you when he is on the ice. He also plays a bit physical and can PK.
Problem is that he is now behind Larsson, Montour, and Borgen on the right side, and Seattle also has Oleksiak who can play the defensive D role, so Fleury is fairly redundant. Someone that could use a defensive RHD should take a flyer on him, he'd be a good pickup imo.