Chief football news reporter Simon Stone:

It seems a long time since Casemiro texted his agent following Manchester United's four-goal hammering at Brentford in August 2023 to say he would 'fix' the problems at Old Trafford and he joined in a deal worth £70m.

As it turned out, the Brazilian was yet another short-term fix for a fundamental problem. After a decent first season, his form collapsed.

By the end of last term, Casemiro had lost his place.

The precise reason for his complete absence from United's FA Cup final matchday squad for their 2-1 win over Manchester City was never properly explained but fundamentally, having been dropped to the bench at Wembley by Ten Hag, the midfielder informed his boss he was not fit enough to be involved.

Casemiro was on the pitch for the post-match celebrations, briefly attended the party that followed but was quickly out of the door and on a private plane with his family to begin their summer, as he had also been dropped by Brazil from their Copa America squad.

That, it was felt, was going to be the end of Casemiro at Manchester United, with a summer move to the Saudi Pro-League anticipated.

Except a deal did not materialise. Casemiro returned for the start of pre-season training, looked fit and did quite well on United's tour of the US.

He started in the Community Shield loss to City in August and has also started all three Premier League games this season.

It is being stressed by club sources the 32-year-old is an example to younger members of the group. He can speak English even though he is not fluent, he trains hard and - occasional flare-ups such as the cup final issue aside - is a positive influence off the pitch.

Club officials were quick to counter social media claims Casemiro left Old Trafford early on Sunday and Ten Hag confirmed he had seen Casemiro in the dressing room after the final whistle.

But the half-time introduction of Collyer because, according to his manager, United needed a more mobile presence in central midfield said everything.

In his prime, Casemiro was one of the most effective defensive midfield players of his generation. As his wife pointed out on social media, he has won every honour in the game.

But top-level football is a brutal business. In the Premier League, reputations count for nothing.

And, sadly for United, in the biggest of games, Casemiro has turned into a liability.

With domestic football taking a pause for the international break, Casemiro will have two weeks before he can put matters right on the pitch, having been dropped again from the Brazil squad.