But after a disastrous spell post the international break in September and a large part of October, United have gone on to rack up an impressive unbeaten run of 16 games in the league. Many will agree that the catalyst behind this unbeaten run has been Michael Carrick's inclusion in the starting XI and his role in how United play.

In order to list down potential candidates, we need to lay down some criteria on the basis of which the players can be judged. And the best place to look for those criteria is Michael Carrick himself. Carrick brings the following qualities to the United team –

b) Passing quality and range – As a deep-lying playmaker, one has to be the starting point of all attacks, which means that the player needs to have really good passing ability as well as the vision to pick out a run ahead of him. One of Carrick’s highlights is his ability to play the ball right into the feet of strikers from a deeper position in his own half. He also has the ability to switch the ball to either flank in order to find the wingers or fullbacks. Michael Carrick has the highest pass accuracy (90%) in the United team and has the 6th highest average pass length (18m) in the United squad amongst outfield players.

c) Shielding the back four – Given that the defensive midfielder is the last line of defence before the back four, it is imperative that he shields them very well. The midfielder has to chip in with tackles and interceptions and do the dirty work when needed. Carrick’s defensive contribution is undermined to a large extent because he is not someone who flies into tackles. But he uses his intelligence to read the game and makes crucial interceptions. In fact, the former Spurs player has the 3rd best interceptions-per-90 minutes ratio in the United squad (2.95 int/90 mins) behind Ander Herrera and Matteo Darmian, while he is also 3rd on the blocked shots-per-90 minutes ratio (0.55 BS/90 mins) behind Phil Jones and Chris Smalling.

1) Marco Verratti – Paris Saint-Germain

Averaging 1.25 key passes-per-game, he is the 4th best in the PSG squad in terms of key passes per game. The Italian certainly has the knack to put in some crunching tackles when required. The tenacious midfielder has won 3.16 tackles-per-90 minutes in the Ligue 1, highest in the PSG squad.

His valuation and PSG’s willingness to let him leave are questions for another day, but he certainly has the ability to fill in Michael Carrick’s big shoes at United.

German midfielder Leon Goretzka isn’t a widely known name. Yet. But his performances for Schalke have been raising a lot of eyebrows recently and have equally drawn praises from all quarters. Goretzka has all the attributes of a fine holding midfielder. He is strong, both in the air and on the ground, has the ability to the shield the defence and break up play, runs the play from midfield into the final third and has an excellent work rate as well.

Goretzka’s contract with Schalke expires in 2018 and a lot of clubs are said to be in the running for the talented midfielder’s signature, if tabloids are to be believed, including Juventus and Liverpool.

3) Julian Weigl -  Borussia Dortmund

Julian Weigl is a 21-year-old defensive midfielder who plays for Borussia Dortmund in the German Bundesliga. Even at such a young age, he has gone on to establish himself as one of the key players in the Dortmund squad since last season. While Pierre-Emerick Aubameyang has been stealing the headlines for his goal scoring exploits week in, week out, Weigl has been playing his part silently, starting off moves from the back which Aubemayang has been able to apply the finishing touches to.

Similar to Carrick, Weigl is also someone who sits in front of the back four and dictates the tempo of the game. His stats are eerily similar to Carrick as well. Weigl has a pass accuracy of 90% in the Bundesliga with an average pass length of 18m. He averages around 77 passes-per-90 mins (as compared to Carrick’s 71 passes-per-90) and also makes an average of 2.6 interceptions-per-90 minutes.

4) William Carvalho – Sporting Lisbon

It’s a surprise that he is still with Sporting Lisbon and it will not be long before a European powerhouse snaps him up. Boasting a pass completion rate of 88% in the Primeira Liga, accompanied by an average of 1.87 interceptions-per-game and 1.2 tackles won-per-90 minutes, Carvalho will add steel as well stability to the United midfield and is also what one would refer to as a ‘typical Jose Mourinho’ player.

5) Daley Blind – Manchester United

Yes, Daley Blind! The Dutchman was an integral part of the United squad under Louis van Gaal, but has seen his game time deplete under Jose Mourinho. However, the Dutch international has played as a defensive midfielder before and his style of play is extremely similar to that of Carrick. Possessing the highest level of football intelligence, Blind has the composure and the range of passing that can match, if not surpass, that of Carrick. Blind has also played at Centre Back and Left Back for United in the last couple of seasons which have definitely improved his defensive side of the game and will help him add that steel in midfield and act as a cover for the back four without being overrun by physical players in the Premier League. Given that there are

Blind has also played at Centre Back and Left Back for United in the last couple of seasons which have definitely improved his defensive side of the game and will help him add that steel in midfield and act as a cover for the back four without being overrun by physical players in the Premier League. Given that there are rumors that United might splurge the cash on Griezmann in the summer, promoting Blind from within the squad can help save some of the money which they might otherwise end up splurging on a Carrick replacement.