Borussia Dortmund chief executive Hans-Joachim Watzke won't rule out selling Robert Lewandowski this summer. Watzke has, however, insisted he won't be sold to Bayern Munich, so leaving the door open to Manchester United and Chelsea.

"I am not saying he will definitely stay but he will certainly not be playing for Bayern in 2013," Watzke said. "Everything else will be discussed with Robert and his advisors in the coming days. Our wish is for Robert to play for Borussia Dortmund next season."