Sir Alex Ferguson has revealed he expects Owen Hargreaves to return from double knee surgery in September.
The England star has not featured since the start of last season following two operations to cure a tendinitis problem that has plagued him since before his move from Bayern Munich two years ago.
"I think we are looking at the end of September depending on how he reacts," said Ferguson.
"We are happy with his rehabilitation so far and while he won't be ready to play in Munich, he will be able to train."
Hargreaves will be joined in Germany by Nemanja Vidic and Antonio Valencia, who have also missed the trip to Malaysia, South Korea and China.
Vidic has not fully recovered from an ankle injury he picked up on international duty with Serbia last month, while Valencia has been unable to play enough part in United's early training sessions because he needed to go back to Ecuador to gain a UK visa.
"It gets frustrating but that is the system and you have to accept it," said Ferguson.
"His fitness levels weren't high enough for him to be considered for the tour."
Ferguson also confirmed another new-boy, Gabriel Oberton, will miss the first three months of the season with an injury which was already known about when he signed from Bordeaux.