Zenit St Petersburg have warned Premier League clubs off Hulk.
The Brazil striker is a target for Chelsea and Tottenham.
Zenit coach Luciano Spalletti said: "He is recovering rapidly. But the exact date [of return], we can not tell you.
"He has exceptional muscle mass, it is difficult to predict anything.
"Let's wait for the forecast of our doctors. And again, Hulk is not for sale."
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