Erik Ten Hag's ability to demand discipline and high standards from his squad will come under scrutiny once again.
Manchester United's head coach now has to deal with the aftermath of Marcus Rashford not attending training after going to a nightclub in Belfast in the early hours of Friday morning, claiming he was unwell later in the day.
United have been told the England international was only out on Wednesday night, but The Athletic has confirmed that the 26-year-old did appear at the Thompsons Garage nightclub in the Northern Ireland capital in the early hours of Friday morning.
This is the second time this season that Ten Hag has faced an issue with Marcus Rashford's clubbing after the striker was criticised by the manager for visiting Manchester's ChinaWhite nightclub hours after Manchester United's defeat to Manchester City. The Dutchman called the move "unacceptable" and called it an "internal matter".
A fundamental part of Ten Hag's management style is to ensure that players play by his rules, often not being soft on those who violate his standards – even at the expense of results on the pitch.
Whether it's banishing Cristiano Ronaldo, banishing Jaden Sancho or replacing Marcus Rashford from the starting line-up after he arrived late for a team meeting in December 2022, Ten Hag has always been committed to maintaining the professionalism of his squad.
And, with Arcelor buying a 25 per cent stake in the club, Ten Hag's long-term future at Old Trafford is in the spotlight and he is needed now more than ever to show control of the dressing room.
Manchester United have won just three of their last 10 games and lost five. They will travel to Newport County on Sunday for an unthinkable opponent in the FA Cup fourth round.
Ten Hag is unlikely to know about Rashford's trip to Belfast and is not blameable for his trip to the capital on Wednesday night, especially as he had already been present in Carrington earlier in the day and coincided with the coach's scheduled Thursday rest day.
Rashford's trip to Belfast included meeting his friend and former Manchester United youth team graduate Ro-Shaun Williams, who signed for Northern Ireland's champions Larne on 25 January. A visit to the club's training facilities was posted on social media.
There is nothing wrong with this in itself, nor should it call into question his judgment. What worries Ten Hag now is what happened later.
The crux of the matter is that Manchester United claim that Marcus Rashford's visit to the Thompsons Garage in the early hours of Thursday night and Friday night was from Wednesday night. But that's not the case. The Athletic contacted Manchester United and Marcus Rashford's camp, but both declined to comment.
Rashford's close contacts said he had returned to Manchester in time for training but was unwell. The private jet he was flying on had landed in the northwest just before 8 a.m. on Friday.
But considering he was in a nightclub just a few hours ago, it's not a good idea – and you can expect Ten Hag to take a similar view.
Although Ten Hag is unlikely to do what he did with Sancho – when he was banished from the first team after he objected to Ten Hag's suggestion that he was not selected for the Arsenal game.
The club's £73 million ($92.8 million) signing said on social media that he had long been a "scapegoat" and in a snarky post actually called United's manager a liar. Ten Hag sought an apology but was not forthcoming, and Jadon Sancho has now returned to Dortmund on loan until the end of the season.
Marcus Rashford's penalty for being late in December 2022 was to be dropped off the bench. He later admitted that "I made a mistake" and said Ten Hag's behaviour was "understandable".
At the time, there was no doubt that Ten Hag's approach was authoritative. He's in control, and the team's upward momentum has been strong in the early days of his tenure.
But a year after that incident, and just a few months before calling Rashford's departure to Chinawhite "unacceptable", his authority will be challenged again – and this time, after a so bad season, you wonder if his message will be accepted.