The trio missed the end of the season with ankle, foot and nose problems respectively.
All three are yet to begin training and will be assessed at the start of next week, before it is decided whether or not they will travel to Thailand on Wednesday for the start of United's five-match summer programme.
"We have a few injury doubts and people coming back from injury," Moyes, speaking at his first press conference as United boss, said.
"They still may go but will be assessed at the start of next week."
Moyes also confirmed new boy Wilfried Zaha will report for duty for the first time on Monday after being given extended leave following the European U21 Championship.
Shinji Kagawa will not link up with his team-mates until United reach Japan on 21 July but Javier Hernandez will miss out completely.