Jadon Sancho is risking his Manchester United career if he refuses to apologise following his public row with manager Erik ten Hag, sources have told ESPN.

Sancho has been ordered to train alone after accusing Ten Hag of lying about the reasons he was dropped for the 3-1 defeat to Arsenal before the international break.

The pair have held talks at Carrington this week but Sancho has refused to say sorry and, until he does, there is no timeframe for his return to the first-team squad.

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Sources have told ESPN that Ten Hag will not back down over his demand for an apology -- both in private and with a public statement -- and if Sancho refuses, it is likely to mean he will leave the club when the transfer window reopens in January.

A brief statement issued by United on Thursday read: "Jadon Sancho will remain on a personal training programme away from the first team group pending resolution of a squad discipline issue."

Sancho is not the first United player asked to apologise to Ten Hag.

When Cristiano Ronaldo was suspended for a game last season after refusing to come on as a substitute in a 2-0 win over Tottenham in October, he was only reintegrated into the squad after showing regret for his actions, which included a statement posted on social media.

Sancho has deleted the social media post in which he accused Ten Hag of making him a "scapegoat for a long time" but has not apologised for the outburst.

A source has told ESPN that part of Sancho's issue is that he feels he has been treated differently to other members of the squad, coupled with a frustration that the club were willing to listen to offers for him in the final week of the transfer window. Late interest from Saudi Pro League side Al Ettifaq came to nothing.

Sancho's future is complicated by his lucrative contract at Old Trafford. The 23-year-old has a deal until 2026 worth more than 300k-a-week, making it difficult to find a club willing to take him on without United having to take a huge financial hit.