The 21-year-old has not been favoured of late by the Portuguese manager and he has subsequently fallen down the pecking order.
Despite finishing as United's top scorer last term, the £36million signing from Monaco is said to believe he is being forced out of Old Trafford.
Mourinho is targeting a summer move for Antoine Griezmann to bolster his forward line.
Anthony Martial has only completed 90 minutes for Manchester United once in the league this season
Paris Saint-Germain apparently want to bring the forward back to France
And according to the Mirror, United are not expected to stand in Martial's way should he look to leave.
Paris Saint-Germain apparently want to bring the forward back to France, having seen him struggle to earn a regular starting role for the Red Devils.
Manchester United sit sixth in the Premier League and have struggled in front of goal beyond Zlatan Ibrahimovic's contributions.
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Mourinho this weekend accused his players of "lacking a winning mentality".
And Martial is claimed to have taken that dig personally, feeling it was aimed at him.
The France international was dropped to the bench in United's midweek 0-0 draw with Hull.
And it remains to be seen if Jose Mourinho will reintroduce Martial at Leicester tomorrow (4pm).