Andreas Christensen has reportedly angered Chelsea boss Maurizio Sarri by leaving the substitutes’ bench during Saturday’s 2-0 defeat to Arsenal.
The Denmark defender has fallen out of favour under Sarri this season and has struggled for first-team minutes.
And The Times claim Christensen went to the dressing room when the Italian made his final substitution with 10 minutes left to play, but did not return to the bench.
He is understood to have told his team-mates that he was going to the toilet, but it remains unclear whether he received permission from Sarri or his coaching staff.
Sarri is believed to be unimpressed by Christensen’s lack of professionalism.
Christensen, who has three-and-a-half years left on his current deal, has been linked with moves to AC Milan and Barcelona, but a Stamford Bridge exit seems unlikely with the club keen to offload 33-year-old Gary Cahill instead.
Christensen has found himself out of Chelsea's first-team this season and being forced to play a back-up role to David Luiz and Antonio Rudiger
Premier League: Appearances – 1 / Minutes – 90
FA Cup: Appearances – 1 / Minutes – 90
Carabao Cup: Appearances – 4 / Minutes – 310
Europa League: Appearances – 6 / Minutes – 540
Sarri questioned his players’ mentality after their performance at the Emirates and is alleged to have held clear-the-air talks with his stars at a training session earlier this week.
Fourth placed Chelsea are now just three points ahead of Arsenal and Manchester United in the race to qualify for next season’s Champions League.
The Blues will have to overturn a 1-0 deficit when they take on Tottenham in the second leg of their Carabao Cup semi-final on Thursday.