Wayne Rooney returned to first team training after a lingering ankle injury this morning along with David De Gea, Antonio Valencia and Ashley Young however wasn't spotted boarding the plane to Anderlecht later on in the day with the rest of the squad.
José Mourinho later confirmed in his pre-match press conference that the 31-year-old isn't yet match fit and "is not confident or happy" but will "see for the weekend" for Manchester United's crunch match against the champions elect Chelsea.
Injuries a huge problem for Rooney this season
Rooney has been limited to just one Premier League start in 2017 as a result of being hit with three injuries since the end of January which has made what it is expected to be his last season at the Red Devils an increasingly frustrating one.
It's unclear whether he would have started tomorrow even if he was fully fit considering the importance of the Europa League to the Old Trafford club but to not even travel with the team is certainly a big blow as Zlatan Ibrahimović's takeover as the main man continues at full steam.
Winger Young is experiencing the same treatment after being in that group of returnees to training this morning but has been snubbed of a seat on the plane because of concerns over his match sharpness, even though a start was unlikely anyway with Luke Shaw showing terrific signs of improvement in the back line.
De Gea and Valencia set to return
De Gea and Valencia were absent at United's 3-0 truimph versus Sunderland on Sunday but both players were spotted at Manchester Airport and linked up with the squad in training prior to the journey.
Despite being included in the 19-man list going over to Belgium it's doubtful that De Gea will start in between the sticks because of Sergio Romero's fine Europa League form, keeping six clean sheets in seven games and conceding just one goal.
Valencia could be in line for a return as a replacement for Matteo Darmian but the Italian defender impressed with Romero at the Stadium of Light last weekend and there would be no complaints if he was to keep his spot at right-back.