Manchester United will take on Swedish side AIK Fotboll in a pre-season friendly with Wayne Rooney missing from the squad amid growing doubts over his future at the club.Rooney pulled out the pre-season trip to Sweden with an injured shoulder, just hours after United confirmed they had "immediately rejected” a second offer from Chelsea for the 27-year-old.The Rooney transfer saga is reportedly unsettling other members of United but the club maintain the striker is not for sale even though he has made it clear he wants to leave.A United spokesman told Press Association Sport: "A bid was received on Sunday and immediately rejected. Our position remains that he is not for sale.”United manager David Moyes insisted Rooney’s injury, picked in a behind-closed-doors match against Real Betis on Saturday, was not serious - there are other matches coming up including Rio Ferdinand’s testimonial on Friday and the Community Shield against Wigan at Wembley on Sunday."Wayne hurt his shoulder in a fall during a match on Saturday,” Moyes told the club’s website. "It’s not too serious and I don’t expect it to keep him out for too long."I’m disappointed he’s missing the game because we were keen to get him back involved and ready to play.”Earlier, United confirmed they had rejected a second bid from Chelsea for Rooney, thought to be for around £25million plus add-ons.Chelsea boss Jose Mourinho has made the England forward his top transfer target and Rooney told former United manager Sir Alex Ferguson last season that he wanted a move.Meanwhile, United’s pursuit of Cesc Fabregas appears to have stalled with Barcelona sporting director Andoni Zubizarreta claiming the Barclays Premier League champions have accepted that he is staying at the Nou Camp.