I think it has less to do with the injuries and more to do with the fact that he's an extremely streaky player. He'll have a stretch of five great games where he's on fire and then disappear for 15 games. And he also never developed into the big power forward who uses his body.
KO is good offensively but is a liability defensively and I think if he goes to Buffalo to play with ROR he will be better off because ROR can compensate for his weak defensive IQ in his own zone. He and JT does not work out because JT is not great in his own zone either although he has improved in past 2 years. Ladd may help in that are because he is good both ways.
I can't deny that I am really disappointing about Nielsen leaving though because he plays so many vital roles on this team but I guess Isles is hoping that Cizikas can step up and play bigger role and fill that void Nielsen left.
Snow did this signing because most GM worry about their job now instead of down the road. If Isles fail to make playoff or play terribly in the playoff next two years, they may lose JT as an UFA in 2018 and he will definitely get fired if that happens. GM does not care about long term job, they want to keep their job now. It is the fans who care about the terms.
I do not think Isles is done. They will do more to improve their RW position either through another UFA signing or more likely through a trade before training camp opens.