Cesc Fabregas and Nemanja Matic were Chelsea's perfect partnership under Jose Mourinho. However, the pair have become competitors under new boss Antonio Conte, with N'Golo Kante having cemented his place in the Italian's starting line-up with a string of dynamic displays.
Conte fought hard to keep Matic at Chelsea in the summer, despite interest from Juventus in signing the Serbia international, and he has preferred the 28-year-old to Fabregas for the majority of the season so far.
However, Matic clearly struggled against Burnley, winning only 25 per cent of his duels, as Sean Dyche's men became one of only a few clubs to out-battle the Premier League leaders this term.
Fabregas is a hugely popular player with the fans due to his exciting style of play, which brings goals and assists to the west London club, and the calls for the Spaniard to start ahead of Matic are getting louder and louder. However, it is hard to argue with the results that Conte has achieved with Kante and Matic in the middle of the park.
Although the latter was poor against Burnley, and gave away the free-kick that led to Robbie Brady's stunning equaliser, Matic is actually the more defensive of the current starting duo at Chelsea, with Kante often left free to drive forward. Indeed, Opta data shows that Matic's average position against Liverpool and Arsenal in February was deeper than that of Kante, while they were similarly placed against Burnley.
I'm arguing the case for Matic's role at Chelsea. He is playing deeper than Kante of late so Fabregas's inclusion would change things a lot pic.twitter.com/gHsUsouNo7— Nizaar Kinsella (@NizaarKinsella) February 22, 2017
Conte is keen to hammer home that his team selections are based on balance and merit, with the likes of Marcos Alonso and Victor Moses having flourished under his tenure despite not being previously regarded as top-class players.
Matic's continued selection can also be attributed to a desire to maintain the equilibrium of the Chelsea starting 11 and recalling Fabregas would affect the role of Kante - who would find life tougher and more restrictive without his gritty Serbian sidekick.
Fabregas has developed well under Conte this season and shown a desire to add extra athleticism to his already impressive repertoire of talents. As the fans chant says, he still has "a magic hat" and is only one assist away from matching his total from last season, despite having only been afforded a fifth of the game time.
The problem is that it is hard to break into a winning team and it looks as though the 3-4-3 formation is here to stay - with Conte keen to find roles for the quality wingers that he inherited upon arriving at Stamford Bridge.
There is hope for Fabregas on the formation front - with Conte having experimented with a 3-5-2 formation on several occasions this season. This is the formation that Conte used at Juventus to get the best out of Andrea Pirlo and the 47-year-old even recently compared Fabregas to the iconic Italian playmaker.
In the 3-4-3 system, Conte used a two-man midfield that needs strong and dynamic players to maintain the balance of the side. Matic has proved since both players arrived at the club in 2014 that he is defensively superior to Fabregas.
It was Matic's job to hold for Fabregas and their partnership brought Mourinho his third Premier League title at Chelsea. The statistics also conclusively prove that the former Benfica man is a specialist in reading the game.
Matic has made 180 interceptions to Fabregas' 56 since August 2016 in the Premier League and dominates the charts in terms of clearances (199/56), duels won (559/408) and tackles (255/205).
The trade-off is clear when you see that Fabregas has contributed to 41 goals since August 2016, with Matic only contributing to 14 in that time, but Conte has goals coming from his front three on a regular basis, as well as his electric wing-backs.
Fabregas has performed well in the 3-4-3 formation against lesser opposition in the cups, but also against Manchester City and Sunderland in the league. He has matched Matic's assist record in the league this season, despite playing in over a third fewer minutes, but he is the ultimate victim of the team's success with their new formation.
Conte obviously still rates Fabregas and he has praised him for maintaining his focus in training - in spite of the ongoing talk of a transfer to AC Milan.
The World Cup winner remains Chelsea's go-to player when they are chasing a game and he has even raised his level in recent weeks to put further pressure on Matic's position. Fabregas realises that creative, intelligent midfielders are now struggling to survive in a sport that has become increasingly physical.
“Today it is more difficult for the talented players to succeed," he told Chelsea TV a fortnight ago. "I don’t think my physical abilities are the best. I’m not the quickest, I’m not the strongest, I’m not the sharpest.
"So, you have to be ahead of the game if a player like me wants to succeed in football. To be a football player today, if you are very strong or you run a lot or stuff like that, it’s easier.
"That’s why I try to get even better because football is growing in a way that before I don’t think it was. Every day you see less talent and more power players running around."
Ultimately, football fans are excited by players with Fabregas's creativity, but Chelsea just need wins as they try to secure a league-and-cup double, and Conte doesn't see anyone as a superstar as he looks for solutions to win as much as possible.
Matic will never be as good to watch as Fabregas, but if he provides the balance for Eden Hazard, Diego Costa and Pedro to fire Chelsea to the title, then few can argue with his inclusion.