The Netherlands international, who previously claimed that he will stay with the North London outfit, is believed to have been a strong summer target for Hamburg.
Despite the German club's initial intentions, it is now understood that the Bundesliga outfit have ended their interest in the midfielder.
"He's a player of great importance for us, a player I count on," ITV Sport quotes Villas-Boas as saying.
"I'm not sure if Hamburg are interested but he's a player who at the moment is not for sale. Anything can happen but he's a player we are counting on."