Argentina striker Tevez is waiting for the High Court to sort out his controversial £30million switch as his former club West Ham argue over who owns him with Iranian businessman Kia Joorabchian.
He told the Daily Mail: "We need a solution quickly so that I can get on with my career.
"To play for a super club like Manchester United without any preseason work behind me is going to be a real handicap."
United remain confident Tevez will be their player before the transfer window closes on August 31 but last night the striker revealed the hold-up has upset him.
He added: "I am a fighter and am prepared for any challenge. In my career I have demonstrated this many times.
"But this is going to be very difficult.
"I desire a swift solution and demand now that all parties arrive at an agreement because I just want to play.
"I am not responsible for all this bureaucracy.
"Mentally I am prepared for to play for United at any moment, but physically it may be more difficult the longer this goes on.
"My hope was I'd be involved in the Community Shield against Chelsea at Wembley on Sunday. That I am not is very painful."
Tevez has been home from the Copa America tournament for almost three weeks but his move to United continues to move painfully slowly.
A court case to decide the matter is scheduled for August 22. But Tevez said: "It has to be sooner than that."