The United manager had challenged the pair to declare themselves fit for Thursday's derby with Manchester City despite each missing the last seven games.

But they have both been ruled out of the clash at the Etihad Stadium, along with Paul Pogba, Zlatan Ibrahimovic, Juan Mata and Marcos Rojo. It leaves United with Eric Bailly and Daley Blind as their only fit senior centre-backs.

However, despite failing to meet his demand, Mourinho insists Smalling and Jones can work their way back into his good books.

Asked whether they had futures at Old Trafford, he said: "Of course they have. I hope this season. I hope this season."

Smalling was also criticised in November following a 3-1 win at Swansea after Mourinho revealed that the defender had declined to play through the pain forcing United to field a makeshift back four.

But Mourinho suggested the unavailability of Smalling and Jones for the derby was not just down to the players.

He added: "It's not just about them. It's about the philosophy and mentality around them. It's not just about them and you know we go with the players we have."

Pushed to clarify what he meant, Mourinho said: "Cautious. Just a cautious approach. It's a profile, it's the philosophy of work. Just that."

Chris Smalling is not fit enough to feature for Manchester United against Manchester City.

Despite missing six first team players, Mourinho has warned Pep Guardiola and Manchester City not to underestimate his team.

United head into the game on the back of three successive Premier League wins and a 23-match unbeaten run in the league that stretches back to October.

He said: "I think maybe opponents they look at us with different eyes because we don't have Zlatan and Paul and Marcos and Mata and Jones and Smalling.

"Maybe they look at us with different eyes but I think they are not stupid, they are not naive and they know that we are going to give them a fight."

United's hectic run-in, that could see them play another nine games if they reach the Europa League final, has been made even more difficult because of their depleted squad.

But Mourinho says the problems have only served to galvanise the rest of his players.

He added: "I think so. I think the boys that are available, I think that they have a great feeling, you know.

"They know that they are important, that they can be important, let's follow the example of Wayne [Rooney] and [Anthony] Martial, they come to a game that we need really to win [against Burnley] and they gave more than expected and Wayne, I didn't think was possible to go for 90 minutes and he did, so I think so.

"I think the fact that we are fighting for important things still is a good motivation to keep people together, to make people make an extra effort.

"Training sessions start at 3 p.m., I was here at 10:30 a.m. and when I arrived some players they were already here, taking care of little details and taking care of their recovery and going to the swimming pool and taking care of their body, that is motivation."