Fletcher is recovering from injury in preseason.
Altidore said: "I remember him when I was at Hull and he was at Burnley. He's always been a fantastic player and the players I've been around that know him have always said positive things about him.
"He's a great striker and works hard but he also has good ability and he could easily play for a bigger club, and this is a big club, but why not? He has all the ability and it will be exciting to have him back."
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