Sporting Lisbon star Van Wolfswinkel: Chelsea, Man Utd rumours not bothering me
The Dutchman's agent has admitted the interest of both Premier League giants.
"I'm always in the sports pages going to a big club," he said, " but I don't pay attention to it. I've spoken to my agent and we've agreed he'll only let me know when there is something concrete.
"As long as I don't hear anything, I won't be thinking about anything.
"Some players have their agents call them after every game, but I'm not like that."