Chelsea followers must now start to prepare for life without Juan Mata, according to Andy Gray.
TalkSPORT reports that the former striker turned football presenter is of the opinion that unless Mata can change Mourinho's usually unerring opinion, he won't remain at Stamford Bridge for long.
Speculation has been rife for the majority of the last few months that Mata, who was voted Chelsea's player of the year last season, will leave the club due to becoming surplus to requirements, and with Mourinho seemingly content to leave him out of the squad altogether, the prospect of a January exit has been given added impetus.
But Gray believes Mourinho is right to stand by his own decisions, and agrees with the idea that the Spaniard could soon be departing the Blues.
"I understand Juan Mata’s a popular lad but when a new manager arrives at a club they're not going to keep everyone happy,” Gray said.
"You are going to have a different opinion to the manager before you.
"He’s walked in there and said he likes Oscar in that middle area. A manager is entitled to make that decision if he feels that way.
"You have to let Mourinho manage. I don’t believe in putting players into teams just because they are good players."
The former Sky Sports presenter went on to reiterate his opinion that Mata will struggle to change Mourinho's mind and earn himself a regular first-team spot.
The Special One is infamous for his steadfastness in leaving star players out of the squad at his own behest, and will not be pressured into fielding anyone he doesn't think merits a place.
"Mourinho is a manager who will pick the best team, he won’t just stick Mata on the pitch to get him on the pitch.
"He’s made his mind up that Oscar is his number 10 and Mata isn’t. I don’t go along with the criticism that he’s getting for leaving him out. Results will dictate whether the pressure begins to grow on Mourinho," added the 57-year-old.