Ole Gunnar Solskjaer turned to Alexis Sanchez instead of Anthony Martial against Chelsea because he was unhappy with the Frenchman's application, according to reports.
Manchester United took the lead at Old Trafford on the weekend when Juan Mata latched onto a Luke Shaw cross to fire home.
But another David De Gea mistake saw Chelsea draw level after a speculative Antonio Rudiger shot was fumbled by the Spanish keeper into the path of Marcos Alonso, who found the back of the net with a chip.
The second half was a flat affair with both clubs incapable of retaining possession in the middle of the park.
Ole Gunnar Solskjaer in 'dressing room rant' at Anthony Martial after Chelsea draw
Twenty five minutes before the end and Manchester United striker Marcus Rashford pulled up with a recurring shoulder injury.
Solskjaer had Sanchez and Martial to pick between on his bench and opted to select the Chilean in place of the former Monaco man.
According to the Daily Mail, this is because the Red Devils boss was unhappy with the Frenchman's attitude on the weekend.
Man Utd keep or sell: Which players will still be at Old Trafford next season?
A video of Martial went viral after the match, showing him standing around instead of warming up before the vital top-four clash against Chelsea.
The Daily Mail reports that Solskjaer even vented his anger at Martial in front of his team-mates in the changing room as a result of his apparent lack of effort.
