In what is being deemed as the 'Judas derby' for one obvious reason, Manchester United will have the opportunity to avenge their last season's 4-0 loss to Chelsea at Stamford Bridge, when lock horns with Antonio Conte's men on familiar yet rather unconquered territory once again. And while things have changed a lot since what transpired last year, one massive thing has changed. It doesn't pertain to the form of the sides or their league positions as compared to last season, but it is about how Nemanja Matic switched for the Blue of London to the Red of Manchester.
 

It would be fair to say that it isn't just the jersey that has changed, but a lot of things have undergone a change because of that. Chelsea fans were open about admitting that they won't miss Matic too much or as much as they may would have missed Diego Costa. But judging by how things have been recently, they may have been forced to change their opinions.
 

When Matic stepped onto the Old Trafford greens in the famed red shirt against West Ham, the influence became very clear. It wasn't just the 4-0 win over the Hammers that stood for it, but Matic's performance on his debut was enough to prove how important a player he will become for United; even more so than how much he was for Chelsea.
 

It seemed strange for many to see Matic ply his trade with United, after having joined from Chelsea; a direct rival. The idea of Chelsea selling a top drawer player to United after he had played a role in helping the club win two titles seemed the most strange part of it all. While it was N'Golo Kante who stole the spotlight much deservedly, the work that Matic did last season went under the radar because of that. If not just that, Matic was criticised for not being quick enough and for a lack of pace. Few realised though, that the manner in which the big Serbian uses his frame and physicality had played a crucial role in helping Kante and in handling the physical aspect of the opposition sides in the 3-4-3 system that Antonio Conte professes.
 

It is obvious that Kante was more influential in Chelsea's march towards the title last season, the manner in which Matic won Chelsea the title under Jose Mourinho in the 2014-15 season served as a testimony to how he will be used at United. Matic played as the sitting midfielder, allowing the likes of Cesc Fabregas, Eden Hazard and Diego Costa the assurance to play without any worries of what will happen at the back. He stood in front of the back four, shielding it by using his strength, big frame and physicality. Chelsea fans don't really remember that, but they miss him now.
 

Chelse did make a financial profit out of the deal when they signed Tiemoue Bakayoko from Monaco for 35 million euros after having offloaded Matic for 40 million euros, but they lack his presence on the pitch. That is largely the reason why Kante isn't having as great a season as he has been having since the last two seasons. He is being forced to deal with things that he never faced with Matic alongside him. 
 

Bakayoko may be an archetypal box to box midfielder, but he sometimes lacks the defensive nous to help out Kante and deny the opposition from overrunning their midfield. It isn't to say that he isn't a good player, but his lack of consistency isn't something Chelsea fans have taken to kindly. Players like Matic allow the side an impeccable balance to the play and the manner in which sides attack looks smooth and pleasing on the eye and that's one of the reasons why Chelsea are somewhat struggling. And it won't be a crime to say that if not for Nemanja Matic, N'Golo Kante may not have won the PFA Player of the Year last season.
 

The manner in which he has been used by Mourinho at United is reminiscent of his usage in the 2014-15 campaign. He allows the currently injured Paul Pogba more freedom to unlock opposition defenses, which he did to near perfection before trotting off injured against Basel in the Champions League. He provides more balance to side, allowing the back four protection and assurance. Largely, he has been one of the United's best players this season and probably the most consistent one.
 

And when United and Chelsea lock horns on Sunday, the role Matic will play will prove to be decisive in who wins the game and loses it. With Kante a doubt, the Serbian may just make the Blues pay.