The 20-year-old's only competitive appearance for the Red Devils since joining up with the Premier League champions' squad in the summer came during the FA Community Shield win over Wigan Athletic at the start of August.
The youngster was immediately loaned back to former club Crystal Palace when he signed for United at the start of 2013, and helped the club secure promotion from the Championship via the play-offs.
Fulham are 10/3 with bet365 to be relegated this season
"He did very well actually in pre-season, so there was no reason to make an enquiry about him," he told reporters.
"I feel that, on the flank, we are OK. We've got five or six, a few options."
The Cottagers are currently struggling for goals having netted just five in seven games, and are in 17th place in the Premier League table with seven points.