Big Sam feels his next switch is a make-or-break one for the 24-year-old England striker.
He said: "The next move is critical for him. It's about playing, improving and scoring goals.
"That next move has to implement all of that for the team he plays for and for him.
"He and that team will be successful. His ability and physical presence is a great asset for him and anyone who works with him.
"He is still developing and is not in his prime. He is still two or so years from his prime."