The academy graduate, 18, has not played for the first-team this season because of an ankle injury. He last appeared for Erik ten Hag&aposs side in July, being forced off less than 10 minutes into their 2-0 defeat to Real Madrid in a pre-season friendly in Houston.
He was, however, included in the matchday squad against Manchester City last Sunday, taking up residency on the bench. Though he was not called upon by Ten Hag, he did store some minutes under his belt just over 48 hours later, starting the Under-21s&apos dramatic EFL Trophy defeat to Salford City.
He played the full duration of the contest at the Peninsula Stadium, meaning he could now be strong enough to make his highly-anticipated return to the first-team. United, on Friday lunchtime, confirmed Casemiro faces &aposseveral weeks&apos on the sidelines through a hamstring injury, meaning his absence could open a window of opportunity for Mainoo.
Mainoo, who also featured for United&aposs Under-19s against FC Copenhagen in the UEFA Youth League last month, made three first-team appearances last month, starting once. He has only made one Premier League appearance so far in his career.
Meanwhile, Facundo Pellistri was also among the players who arrived at Stockport railway station on Friday afternoon. The Uruguayan has been left out of United&aposs last two matchday squads.
Manchester United squad travel to London for Fulham fixture – pictures
However, Victor Lindelof was not seen, meaning he looks set to miss the lunchtime kick-off. Ten Hag, speaking to the media on Friday lunchtime, confirmed he was a doubt because of illness.
