Most of these guys were had career threatening injury at times that full recovery was doubtful. Unfair to add them to this list cos they weren't even playing enough anymore. That said, Andrei Kirilenko had like one good Jazz year and sort of felt irrelevant afterwards.
Michael Redd comes to mind as another player who felt irrelevant after that all-star run
Can't say Roy, he was outta the league cos of his knees at 26/27.
This may be a spicy take, but I would say Vince Carter. His Nets stint was meh at best.
Also, notable folks would be Rudy Gay, Andrei Kirilenko, Roy Hibbert.
Sadly, Brandon Jennings. Michael Carter Williams. Tyreek Evans. Adam Morrison. They broke out that first year but never amounted to anything afterwards.
Andrea Barniani
Michael Kidd Gilchrist
He has a clunky looking jumpshot that doesn't feel like it'll ever go in but does for some reason. He also has one gear which is going fast only, reminds me of a young Devin Harris.
Manimal. This guy was a beast in the boards and had such a high motor then. Too bad he couldn't develop a jumpshot to save his career.