The last time Erik ten Hag noticed a dip in Jadon Sancho‘s training levels, the Manchester United manager put an arm around the player’s shoulder and ushered him away from the spotlight to deal with his physical and mental issues.

Sancho trained alone for eight weeks during the World Cup in December, including a spell in the safe surroundings of Dutch amateur club OJC Rosmalen where he worked with coaches trusted by Ten Hag. He did not play for United for more than three months.

After Sancho was re-integrated into the squad at the end of January, it was seen as a victory for Ten Hag’s man-management and pastoral care.

When the Dutchman had reason to question Sancho’s effort and attitude again ahead of Sunday’s defeat at Arsenal, however, the response was less compassionate and rather more combustible.

Ten Hag said Sancho had been left in Manchester due to his performance in training. The 23-year-old reacted furiously on social media, effectively accusing his manager of lying and making him a scapegoat.

Jadon Sancho is the talk of the town at the moment after his social media outburst on Sunday

Sancho has struggled to reach his potential at Manchester United after his move to Old Trafford three years ago

The fall-out has plunged Sancho’s future at Old Trafford into doubt at the end of a summer in which United were prepared to listen to offers of £45million for him.

The fact that the transfer window is only open in a handful of countries may mean that he has to stay for now, but for how much longer?

Cristiano Ronaldo was kicked out of the club for publicly challenging Ten Hag , and Sancho is a significantly softer target.

Whether that happens remains to be seen but the issue has once again dredged up the disciplinary problems and personal issues that have hung over the gifted winger throughout his career like a bad smell.

It is understood that Chelsea considered signing Sancho this summer but were concerned about his mindset and went for Manchester City’s Cole Palmer instead.

Gareth Southgate continues to give Sancho a wide berth, and his name was well away from the conversation when the England manager named his squad for the upcoming Euro qualifier against Ukraine and friendly against Scotland.

Mail Sport understands Southgate and his coaching staff have spoken about the problem of Sancho sulking when he is not selected in the line-up and the negative impact it can have on the atmosphere in camp.

The issue dates back to Euro 2020 when he is said to have reacted petulantly to being left out of the squad for the opening group game against Croatia.

United boss Erik ten Hag (left) has blasted Sancho (right) for his performance levels

He started another five matches on the bench at the tournament because Southgate felt that Sancho’s training levels were not up to scratch, the same issue now raised by Ten Hag.

His only call-up since then was in an experimental side for a World Cup qualifier against Andorra two years ago when Sancho was late for a team meeting and subsequently missed out on a place in Qatar.

Time-keeping has become a perennial problem for one of English football’s hottest properties.

Sancho was voted player of the tournament when England Under 17s finished runners-up in the 2017 European Championship, and had already joined Borussia Dortmund for £8million after rejecting a new contract offer from Manchester City by the time England won the Under 17 World Cup later that year.

A few months on, Sancho and his former City team-mate Phil Foden were dropped from the England Under 19s side against Latvia after turning up late for a team meeting.

It was a recurring issue at Dortmund where manager Lucien Favre punished him on several occasions and dropped him for games against Barcelona and Borussia Monchengladbach.

Sancho was also fined by the German FA for breaking lockdown rules in order to get a haircut.

‘He just has to be smarter and grow up with things like that. You have to lead Jadon the right way,’ lamented his team-mate Emre Can.

Sancho’s time-keeping has become a perennial problem for him at club and country

Concerns over Sancho’s attitude remains and the player has hit a dead end too often

Concerns over Sancho’s attitude remained as United launched a bid to sign him that went on for well over a year and ended with a £73m transfer in the summer of 2021.

The boy who grew up playing on a tough Kennington estate in south London returned to Manchester talking about his love of street football. Sadly, he has hit a dead end at United far too often.

Think of a highlight reel of Sancho’s Old Trafford career so far and they are few and far between. A total of 12 goals and six assists from 82 games is a poor return on United’s investment.

He impressed on tour last summer following Ten Hag’s arrival before starting the season well, and then did a decent job as a false nine during this pre-season. But where are the fireworks?

Sancho has struggled to reproduce his Bundesliga form in the more demanding surroundings of the Premier League

Mail Sport understands Gareth Southgate (left) and his coaching staff have spoken about the problem of Sancho sulking when he is not selected in the line-up for England

Sancho has struggled to reproduce his Bundesliga form in the more demanding surroundings of the Premier League where even players with his talent cannot get away with cutting corners if they want a regular place in the team.

Marcus Rashford scored 30 goals off the left wing for United last season and Antony was always likely to start on the right after following Ten Hag to Old Trafford from Ajax for £81.3m.

Alejandro Garnacho and Facundo Pellistri are chomping at the bit, while Mason Mount and Bruno Fernandes can both play in the wide areas.

With a basic wage of £250,000 a week, Sancho is no longer a prospect. A player with potential. He has to be the real deal for United, but he is running out of chances to prove it.