The England captain, deployed in a central midfield role this season, has been a peripheral figure in a team struggling to gel and his lacklustre performance in the 3-1 defeat at Watford on Sunday led to widespread calls for him to be dropped.
Rooney mustered one shot, did not play a single through ball and created only two chances for team mates with the nine corners and free kicks he took.
His defensive contribution was also negligible, failing to make a single tackle and registering one block and one interception in a tetchy 90 minutes during which his main priority appeared to be engaging in a constant dialogue with referee Michael Oliver.
“Alex Ferguson knew it more than three years ago...Wayne Rooney is no longer worth a place in the Manchester United team,” veteran United watcher Jim White wrote in the Daily Telegraph.
“Slow of thought and legs, United are a side currently functioning as if running through custard and much of the blame lies with the continued selection, in the most critical position in the team, of a man who is playing on his reputation.”
Mourinho has never been afraid to make tough decisions during his trophy-laden managerial career and he faces a huge one on the 30-year-old Rooney, who is four goals short of overtaking Bobby Charlton as the club’s all-time leading scorer.