The Japanese midfielder has voiced his unhappiness at a lack of minutes at Old Trafford this season, saying "Please ask David Moyes why I'm not in the side," when questioned about his situation.
However, Moyes has insisted that there is a simple explanation for Kagawa's exclusion to date - a pre-season disrupted by a Confederations Cup campaign and two trips to the Far East on international duty.
"There are quite a lot of players who have not featured yet," Moyes told reporters.
"But if you look at it most of them were late back from international duty after the Confederations Cup, then they were away for a friendly international and a long-haul flight, then they were away again for another international.
"If you look at the reasons why people haven't played, it is more to do with them not being available for that to happen."
Kagawa, who cost United £12m to sign from Borussia Dortmund in 2012, scored six goals in 20 Premier League appearances for the Red Devils last season.