Their much-changed line-up boasted quality but looked cumbersome and unwieldy in Rotterdam, where Feyenoord snatched a 1-0 win through Vilhena’s strike.
It was hardly the response Jose Mourinho craved after Saturday’s derby defeat at home to Manchester City, with few of the eight changes doing themselves any favors.
Marcus Rashford has been blazing a trail through English football since announcing his arrival in this competition nearly seven months ago, but he left after 63 minutes having given plenty of effort with precious little to show for it.
Anthony Martial continues to search in vain for the spark that lit up his first season at Old Trafford. Matteo Darmian and Marcos Rojo were poor replacements at full back for Antonia Valencia and Luke Shaw, left at home with Wayne Rooney to prepare for Watford on Sunday.
While United were lacklustre going forward, Mourinho insisted his side did not deserve to lose.
“Of course I am unhappy, especially because the way the game was going in the moment we don’t deserve to lose,” he said on BT Sport 3.
“In the second half we were always in control, we were trying to win the game and they were trying not to lose the game.
“In that moment we were pushing and they capitalised because it is exactly at that moment where we lose the game. We were double unlucky because it’s a clear offside.”
Mourinho made eight changes from the side which lost the Manchester derby on Saturday, but the Portuguese did not want to discuss individual performances or comment on whether those players given their chance had passed it up in the defeat.
“I don’t want to go in that direction, I don’t want to personalise it,” he said.
“Some of the players were playing their first minutes of the season, there have not been many minutes for them, but obviously some played better than others. I cannot judge them only on one game.”
However, Mourinho said he would revert to a “normal team” for Sunday’s trip to Watford, with the likes of Antonio Valencia and Luke Shaw set to return.