Messi refused to rule out leaving the Nou Camp next summer in an interview with Ole this week.
Asked about his star man's situation, Martino remarked: "When you see the connection he has with Barcelona, ??it seems difficult (to leave the club). When you see the options out there in the world, bigger teams where he would fit perfectly, I think it's possible.
"But ultimately I think he should make sure to be happy where he plays his football."
The former Barca coach added: "I have never spoken about this issue with him, each person can make of this what they please.
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