United earlier published a statement on their website revealing the reason for Martial's omission.
MUTV later claimed that Martial had suffered an injury in training.
Here is what the boss had to say after the game in his post-match interview with MUTV...
"He was injured in the Friday training session and yesterday (Saturday) he couldn't train".
"If one year it's not possible, a lot of people will say that we have failed - but that's not true". Let's wait and see, also for Romelu.
Martial was at Old Trafford today, but left three hours before kick off. MUTV have said that Martial is injured, although that might not be the whole story.
12 goals makes this season the most prolific of Rashford's young career, but most of those goals came during the first half of the campaign.
"I've done it because I think in these last few matches of the season everyone deserves a start".
There has been much speculation over what players are likely to depart in the summer with Luke Shaw, Daley Blind and Marcos Rojo appearing destined for the exit door, while the future of Marouane Fellaini remains very much up in the air. The assistant coach has long supported Mourinho and allied with him even when times looked bleak at Chelsea and Real Madrid.
Get the latest World Cup news updates.
"That is the hardest thing for me but his happiness is more important and, of course, I respect his decision".
Mourinho also confirmed that Carrick will be substituted during the game, to ensure he is given a send-off by the club's fans.
"It's all about having a attractive day and saying goodbye to Michael Carrick in the best way possible", said Herrera.
"I'm sure the owner will try to improve the level of the squad and the team, try to improve the position in the table".
"He is the coach, he decides and I accept and I respond on the pitch".