Hazard, 27, has enjoyed a scintillating start to the new season, having scored five league goals as the Blues sit as joint Premier League leaders after stretching their unbeaten streak to five games.
But who will Sarri pick to lead the line at the London Stadium?
Even though the Hammers are now languishing at the bottom but clearly Manuel Pellegrini's men have the firepower to cause an upset which Maurizio Sarri will be very much aware of.
"Maybe in a few years Eden can win the Ballon d'Or because he is a very good player".
Zabaleta will surely hold all the aces with a good display in Sunday's home fixture against Chelsea, as he will be coming up against arguably the best player in the Premier League right now.
"Alvaro has to gain confidence with one, two, three goals", Sarri said after the victory, during which Morata missed a number of chances.
Sarri said he needs goals to boost his fragile confidence following Chelsea's 1-0 win against PAOK of Greece in their Europa League opener on Thursday, for which he was back in the starting line-up.
Belgium worldwide Hazard scored a superb hat-trick in Chelsea's emphatic victory over Cardiff City last weekend.
This is also very important for the team because he is a very important player for the team.
"It has always been a fair competition between us and we will both try to step up to help the team reach our target", he told London's Evening Standard.