Now Mourinho's men are out to capitalise on last Thursday's 1-1 draw in Russian Federation and book a place in the quarter-finals of a European competition the Reds are aiming to win for the first time.
Making matters worse for Mourinho, Paul Pogba and Daley Blind suffered injuries in the win over Rostov.
"They simply don't care", Mourinho said after United reached the Europa League quarterfinals by beating Rostov 1-0.
Guy Mowbray: "With Jose Mourinho stressing that United have 'lots of enemies' this week, it might have been nice for him to catch up with a friend".
"Play on Monday with 10 men, enjoying five hours the M6 coming back to Manchester". We have to wake up at seven o'clock to eat and come to the game.
Earlier, in a less confrontational mood, Mourinho told the BBC ahead of the Rostov game that he felt United had made mistakes in the transfer market before he arrived at Old Trafford.
Mourinho is hopeful Pogba, who has had an inconsistent season following his world record move from Juventus, will be ready after the next global break.
And Mourinho has called for the Premier League to help protect English clubs as they challenge in Europe's top cup competitions.
Warming to his theme, Mourinho suggested the compression of matches meant United were likely to lose at struggling Middlesbrough, who on Thursday sacked his former Real Madrid assistant Aitor Karanka.
"He is from a working family, a family with three boys and I am sure they need a lot of food on their table each day because they are all giants so I am sure that the mum and dad had to work hard for many, many years for them".
"The boys are incredible boys".
'It will be a tough game, but we need to be ready for it'. "Fatigue has a price". "Whoever decided the Monday and Sunday games probably thinks the same way".
"This is Manchester United, I don't sacrifice anything", he said.
But Keane ridiculed that opinion, saying: "I've never heard so much rubbish in my life". But it's not to laugh at all.
United prevailed on the night thanks to a 70th-minute goal by Juan Mata, who finished from close range after Zlatan Ibrahimovic had flicked Henrikh Mkhitaryan's cross towards goal.
Manchester United have drawn Belgian side Anderlecht in the Europa League quarter-finals.
"We should be the last team to play at the weekend".
"The fans will give us this extra energy so we believe that tomorrow we can cope with the situation and fight to be in the quarter-final".