Jose Mourinho has indicated a belief that some of his Manchester United players do not have the mentality required to make the club successful again.

Mourinho was careful not to identify which players he feels are falling short, but several members of his first-team squad have fallen out of favour this season.

Anthony Martial, Luke Shaw, Jesse Lingard and Chris Smalling are most significant players to have seen their starting opportunities in Premier League matches limited under Mourinho.

For Martial in particular, the lack of chances has become frustrating, with the player understood to be unhappy at being dropped for Wednesday’s 0-0 draw at home to Hull despite setting up two goals in the 4-0 FA Cup victory over Wigan three days earlier.

Mourinho has suggested that some of his players have drifted into a comfort zone, and are satisfied with pushing for Champions League qualification and winning the occasional trophy, having not secured the Premier League title since Sir Alex Ferguson retired in 2013.

The manager added that one of the difficulties he faced after replacing Louis van Gaal as manager last May was working out which of his players were falling short of the standards he demands.

He said: “I didn’t know the players very well. I didn’t know that some players need time to live with this, because it must be part of your natural habitat.

“Play to win, responsibility to win, cope with the pressure to win. This is something that has to belong to your natural habitat. For some guys, it doesn’t.

“They also need that time to go out of their comfort zone or a zone where they are protected that we assume the objective is not to win, that also takes time.”

United are unbeaten in 14 Premier League matches – a run stretching back to October 23 – as they prepare for Sunday’s trip to Leicester.

But seven of the games in that run were draws, including each of their last three league matches, against Liverpool, Stoke and Hull.

Martial has only managed six goals so far this season (Getty)

No team have drawn more Premier League matches than United this season, nine in total, and that is a significant reason as to why they start the weekend in sixth place, 14 points behind leaders Chelsea.

Yet even though the Premier League title is realistically out of reach this season, Mourinho has no regrets about declaring his ambition to make United champions again.

He said: “I was speaking about being champions because I don’t think there is another position that a manager can have at this club.

“It would be easy for me to say that we want to play better, that we want to improve the quality of my game, that we want to improve the relationship between the players and the fans.

“And I do want the fans to feel again more connected with the team and style of play.”

Mourinho has admitted that United have to improve their scoring record, having managed only 33 Premier League goals this season, 15 fewer than Chelsea and 19 behind top scorers Liverpool.

Mourinho makes no secret of his desire to win trophies at United (Getty)

But he insists that their style of attacking play has deserved more goals, and suggested that his Premier League rivals are getting more credit for their forward play despite being less offensive, in what could be perceived as a criticism of Chelsea.

He said: “There are teams that are very defensive, and with the first shot, they score, and the second shot, they score, and then you chase the goals and the power of the numbers, and you say that the team is magnificent.