Erik ten Hag faces his biggest test as Manchester United boss when his side travels to the Etihad to take on Manchester City on Sunday afternoon.
The Red Devils have won each of their last four games in the Premier League but haven't played in the Premier League for nearly a month, with a combination of the Queen's death and the international break bringing an end to United's momentum.
After suffering back-to-back defeats against Brighton and Brentford in his two opening fixtures, Ten Hag looked doomed to be another failed United manager but his side have bounced back with impressive wins over Liverpool, Southampton, Leicester City and Arsenal.
While Scott McTominay has silenced critics with some eye-catching form in those games, earning above a 7/10 rating from WhoScored in three of his last four Premier League appearances, Manchester City presents a very different challenge for United.
Considering the huge threat posed by City's creative players, perhaps most notably Kevin de Bruyne, Ten Hag should consider handing Casemiro his first Premier League start.
De Bruyne has six assists in his first six Premier League games of the season, so is clearly on top form at the moment, and must be nullified if United are going to take anything from the game.
The Brazilan joined United from Champions League winners Real Madrid during the summer, having become one of the most decorated players of all time during his time with Los Blancos.
When he joined, Rio Ferdinand was full of praise for the 30-year-old, saying:
"First and foremost, the guy's a real winner, he knows how to win, he's been integral in everything positive about Real Madrid in recent years."
The £300k-per-week midfielder is something of an expert when it comes to winning and has a CV filled with experience in big matches, so he could be the ideal man to stop De Bruyne on Sunday.
Last season saw Casemiro average more tackles, interceptions and blocks than McTominay would in the Premier League, which suggests that he holds the edge when it comes to defending his own goal.
Casemiro started when Real Madrid triumphed over Manchester City in the Champions League last season so he knows what it takes to defeat Pep Guardiola's side and his immense experience and ability mark him out as the ideal man to stop De Bruyne from running the show at the Etihad this weekend.