Manchester United hero set the standard for Casemiro's debut back in 2017

Before the recent signing of Casemiro, the last time Manchester United signed a defensive midfielder was in 2017 when they secured the signature of Nemanja Matic from Chelsea for £40m. It became apparent over the next few years that while he was technically secure, the Serbian was physically declining.

This is why many fans had reservations about the club spending £70m on Casemiro. At 30 years old he has shown no sign of declining so far but this might be the case over the next few years.

However right now United have one of the best defensive midfielders in world football and after earning his visa he will likely make his debut against Southampton. And although Matic began to decline after his first season, his debut against West Ham United set the tone for what will be expected of the Brazilian on Saturday.

READ MORE: United receive surprise Cody Gakpo transfer boost

After winning the Europa League and the League Cup in his first season, Jose Mourinho needed reinforcements. So in the transfer window he brought in Romelu Lukaku, Victor Lindelof and his former midfield general Matic ahead of the 2017/18 season.

Their first challenge would be against West Ham. United would win the game 4-0 thanks to a brace from Lukaku and goals from Anthony Martial and Paul Pogba.

But despite the outstanding attacking performance, the plaudits went to Matic who won the Man of the Match on the day. Throughout Mourinho's first season at the club, United had mainly focused their attacking play through Zlatan Ibrahimovic so the addition of Lukaku was needed, but they also at times lacked significant fight in the midfield.

Matic solved this problem and then some, but then he also added a lot to the team in possession being able to reliably