Jamie Redknapp claimed Arsenal boss Mikel Arteta would have been "dancing around his living room" when Manchester United midfielder Casemiro picked up a yellow card that will now rule him out of Sunday's showdown.
The two teams meet at the Emirates this weekend in a clash that could have a huge impact on the title race, but United failed to make ground on the Gunners with their 1-1 draw at Crystal Palace on Wednesday evening. Bruno Fernandes fired the Red Devils in front, but a 91st minue Michael Olise free-kick broke United hearts.
It also robbed Erik ten Hag's side of the chance to leapfrog local rivals Manchester City into second and close the gap with table-toppers Arsenal. However, his main concern will be how he sets up against the Gunners without his main-man in midfield.
Arteta's side have put many teams to the sword this season and their own midfield dynamic has arguably been the biggest factor in their fine form.
Few teams have been able to deal with the likes of Martin Odegaard, Granit Xhaka and Thomas Partey all working in tandem and United will now have to try and do so without their £60million-enforcer.
Mikel Arteta's dream Arsenal line up as last-gasp January transfers are securedFollowing Casemiro's fifth booking of the season, Redknapp told Sky Sports: "We spoke before the game about Casemiro and the importance of not getting a yellow card because they need him on Sunday.
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"He gets booked in the 80th minute and it’s as if from that moment, it took the steam out of Manchester United.
"It affected them so much and it’s as if they knew that their talisman in that midfield role is gone, it’s a bit of a moment of madness. He is furious with his team-mate Bruno Fernandes for getting out of the way of the challenge."
Redknapp went on to make his claim surrounding how the yellow card would have gone down in the home of the Arsenal boss, who was surely watching his next opponents in action.
"I bet when Mikel Arteta saw that, he was dancing around his living room because it is so important. They have no one that can do that in their team."
Arteta is likely to now divert his attention to Thursday night's offering of second-placed City taking on the Gunners' most fierce rivals Tottenham at the Etihad.
If the Spaniard finds it just too difficult to cheer for Arsenal's arch-enemies, a draw between City and Spurs would still give the Gunners the chance to go 10 points clear if they do their job against a Casemiro-less United on Sunday.