United’s first Premier League away trip of the season ended in a 3-2 defeat at Brighton and Hove Albion on Sunday.
The poor result and lacklustre performance followed a summer of tension and frustration at United, with Mourinho disappointed by a lack of support in the transfer market.
Jose Mourinho's summer of misery
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Zinedine Zidane, the former Real Madrid manager, has been touted as a possible replacement should Mourinho lose his job.
Senior sources at United have dismissed any interest in Zidane, however, insisting that there is no potential vacancy to discuss.
Mourinho signed a new United contract in January, extending his stay at Old Trafford until 2020 with the option of a further year.
The Portuguese hoped to add a central defender and a wide player to his squad during the summer transfer window but was left disappointed on both counts.
United made only three signings - midfielder Fred from Shakhtar Donetsk, teenage full-back Diogo Dalot from Porto and reserve goalkeeper Lee Grant.
It is understood that while Mourinho wished to sign experienced players at the peak of their careers, executive vice-chairman Ed Woodward sought younger players who could be developed.
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