Hazard vs Messi
The man who wants the throne vs the King. People have always tried to put Hazard is the same bracket as Messi, Ronaldo and Neymar. The problem with that comparison is that Hazard has never proved himself on the big stage. His goals have been brilliant for Chelsea in the Premier League and his brilliant runs through the opposition might be "Messi-esque". However, to prove that he is up there he has to deliver in the Barcelona match.
This contest isn't only about Hazard proving himself, it is also about Messi exercising his demons. Lionel Messi has a strange record against Chelsea, they are his bogey team as he has never scored against them. Tuesday will be important for both these top players.
Luis Suarez threat
While everyone may be concentrating on Messi, Chelsea might forget that Barcelona have a bigger threat. Luis Suarez is familiar with English teams and he relishes playing against them.
He might be older and his goal scoring abilities might be on the wane, but he has the ability to turn up at the right place and time. The fact that he has scored seven goals in 2018 should make him a potential threat for Chelsea.
Fabregas vs Iniesta
Iniesta is not the player he was, especially with his ageing limbs. However, his intelligence and ability to play the killer pass makes up for his weakness . Chelsea have a player of such ilk in their ranks as well in Cesc Fabregas, who is known to have a killer ball or two in his armoury.
With Coutinho ineligible for the game against Chelsea, Iniesta will line up against his former team-mate. It will be interesting to see how the two provide creativity to their teams.
The Willian effect
While Barcelona have Luis Suarez, Chelsea have Willian. The man has been in scintillating form and has an ability to turn up during big games. Barcelona will have a tough time handling him and Hazard on either sides of the wing.
His double against Hull will boost his confidence and with 10 goals and and as many assists this season, he is a player Barcelona can't take lightly.
Off the ball
Antonio Conte stated in the press conference after the win against Hull that he has studied Barcelona for a month and found a weakness.
The Italian feels Barcelona are good with the ball at their feet but their deficiency is apparent when they don't have the ball. So could we see a scenario where Chelsea actually keep the ball and have a higher possession than Barcelona? We'll find out this Tuesday!