Martial has started less than half of United's 38 Premier League games this season.
But there was still a moment to remember late on as Carrick's 464th United appearance came to a close, receiving a standing ovation as he was replaced by Paul Pogba on a day that belonged to one of the club's most distinguished servants.
"When he has his badges, when he has his pro licence, when he makes the bridge from player to assistant". I have nobody in the world of football ready to be assistant manager.
"I'm going to have assistant coaches, I'm going to have fitness coaches, and a structure where they have specialists in different areas connected to the performance".
United - who round off their Premier League campaign against Watford on Sunday and then face Chelsea in the FA Cup final - wished him well after his two years at the club. "You know why now", Mourinho said.
Addressing the fans, Carrick added: "I'd like to say a massive thank you to everyone for their support over the years, it's been unbelievable". If Eden Hazard goes to Real Madrid, I'm sure Chelsea would be keen on a swap deal.
"17 years and the kid is now a man".
And it was the former England midfielder who made the decisive contribution, his superb lifted throughball enabling Juan Mata to tee up Marcus Rashford to break the deadlock.
But Mourinho insisted his absence was purely down to an injury that could also see him miss next Saturday's showpiece.
Lukaku, United's leading scorer in the league with 16, sustained an ankle injury in last month's victory over Arsenal and travelled back to Belgium to recover.
"He was injured in the Friday training session and yesterday [Saturday] he could not train". "He had treatment in the morning [on Sunday] at the training ground".
Early on United played with a lack of intensity perhaps befitting of a side focused on a cup final.