Man Utd fall apart without Casemiro! All the matches Erik ten Hag's team have played without the Brazilian in the starting line-up

After a really encouraging pre-season campaign, there was a huge sense of optimism ahead of United's opening game of the campaign at home to Brighton.

That was quickly replaced by a sense of doom when United were overran in midfield by Moises Caicedo and Pascal Gross, who scored twice in the first half.

Despite a summer of renewal with Ten Hag, United's backbone was still 'McFred', Scott McTominay and Fred, and it was painfully obvious new blood was needed in midfield.

If Brighton was a warning of the coming storm, Brentford was the hurricane.

United were picked apart by Thomas Frank's side in one of the club's most humiliating Premier League results, and people were already questioning whether Ten Hag could sort out the mess.

Meanwhile, from his home in Madrid, Casemiro was watching with interest. United had spoken to his agent about a possible move as he was at risk of being usurped as first-choice holding midfielder in Carlo Ancelotti's starting line-up by the signing of Aurelien Tchouameni.

"Tell them I'll fix this", Casemiro reportedly told his agent, urging him to answer United's call.

Casemiro officially completed his move from Madrid to United worth £70 million on the day of the match with Liverpool, but his arrival did little to stem fans' fury against the Glazer ownership.

He was welcomed by fans, but the applause for him was drowned out by "We want Glazers out" chants.

United did not need him on this occasion, storming to victory thanks to goals from Jadon Sancho and Marcus Rashford.

The Brazilian made his debut in a 10-minute cameo off the bench in relatively comfortable victory, as Bruno Fernandes scored the only goal.

Casemiro got a longer run out in his second appearance, playing 31 minutes at the King Power Stadium. Jadon Sancho scored the only goal.

Despite having two warm-up appearances, Ten Hag still didn't think Casemiro was ready to start against Premier League leaders Arsenal.

He did, however, hand a debut to new signing Antony, who scored the opening goal.

Casemiro, meanwhile, was brought on for 10 minutes, when United were already 3-1 up.

Casemiro got his first start in the 1-0 home defeat by Real Sociedad and was benched for the next game away to Sheriff.

United were leading 2-0 at half-time when he was brought on for Scott McTominay, helping the team see out the result.

It was a big shock to not see Casemiro in the starting line-up for the first Manchester derby of Ten Hag's reign, and the midfielder's exclusion led to more speculation that the Dutch coach was not sure about his adaptability to the Premier League.

But when City ran riot in the first half, going 4-0 up, it was evident United did need the midfielder's experience and dynamism.

His introduction in the 59th minute could not help turn the tide, but at least while he was on the pitch, United scored twice and conceded only twice.

Ten Hag learned his lesson, and Casemiro started the next 10 games in all competitions, with United winning seven of them.

Casemiro was given a rest for the first Carabao Cup game of the season, four days after losing away to Villa in the league.

The team managed to twice come from behind to take the lead by the team he was introduced in the 82nd minute.

After starting five matches in a row, the Brazilian was benched against League One Charlton, with teenager Kobbie Mainoo starting in his place.

He was brought on with half an hour to go, when the score was 1-0, and helped make sure of the win.

A late yellow card against Crystal Palace meant Casemiro was suspended for the trip to Arsenal, and this time his absence was felt far more keenly.

The Gunners dominated the latter stages of the game after Lisandro Martinez had pulled United level, and Eddie Nketiah won the match in added time as the Red Devils failed to get a grip on their midfield.

This was the first test of United's reliance on Casemiro after he was banned for three games for being sent off against Crystal Palace. They badly failed it, with Leeds over-powering Marcel Sabitzer and Fred in the middle.

Wilfried Gnonto enjoyed the freedom of Old Trafford to put Leeds ahead in the first minute while a Raphael Varane own goal gave the struggling visitors a second goal shortly after the break.

United salvaged a draw through goals from Marcus Rashford and Sancho, but the scrappy performance was a reminder of how everything can fall apart without Casemiro.

Ten Hag's side fared much better at Elland Road in the second game of Casemiro's ban.

Fred and Sabitzer dominated the midfield in a cagey game that was won by late strikes from Rashford and Alejandro Garnacho.

United emerged unblemished from the final game of Casemiro's ban, but the scoreline flattered them.

Leicester missed a glut of first-half chances before Rashford struck, and if it hadn't been for two top-class saves from David de Gea, it could have been a very different story.

Depite the win, this was another reminded of United's reliance on Casemiro.

Casemiro was one of five players rested after the Carabao Cup final win over Newcastle.

But predictably, he was the first player called upon to sort things out after a drab first half when West Ham missed two big chances.

The Hammers still took the lead after he came on at the start of the second half, but Casemiro helped inspire the comeback, proving his value to the team once more.