Under-fire Manchester United manager Jose Mourinho believes some of his misfiring squad are hurting more than others as speculation mounts over whether the Portuguese coach's time in charge at Old Trafford is coming to an end.

A third defeat in seven Premier League games at West Ham on Saturday saw United already fall nine points adrift of leaders and fierce rivals Manchester City and Liverpool.

Ahead of Tuesday's Champions League clash with Valencia, Mourinho insisted he doesn't fear for his job but refused to state whether he had met with the club's executive vice-chairman Ed Woodward in the past few days.

Mourinho also defended his players from accusations of not trying hard enough, but believes some are taking a slump in form more to heart than others.

"I think that some care more than others," said Mourinho.

"After 20 years of football, I'm still the kid I was. I'm still naive, but I still don't believe that a player is not honest.

"Until somebody that was a big professional player says 'I was a dishonest player', I will always believe the players are honest players and want to give their best."

Mourinho also laughed off speculation he has been contacted by former Real Madrid boss Zinedine Zidane, the favourite to replace him in the Old Trafford hot seat if Mourinho is dismissed.

A report in The Sun newspaper on Monday claimed Zidane had phoned Mourinho to reassure him the Frenchman isn't plotting to take his job.

When asked about the story, Mourinho turned the tables on the journalist who wrote the story by telling reporters to ask him whether the story was true and joked his phone had been bugged.

Zidane resigned as Madrid coach in June after leading the Spanish giants to three consecutive Champions League titles.