The Premier League and FA Cup holders face off at 3:00pm British Time this Sunday.
Writing in his Sky Sports column, Merson predicted a 1-0 win for Arsenal, citing the significance placed on the game as being greater for the north London club.
"I would say this game means more to Arsenal than it does to Chelsea and I think that, when it is like that, the team it matters most to usually win," Merson said on Sky Sports.
"Chelsea will have been in America playing big games and I just think that Arsenal will be up for it more, as they were against City last year. And when that happens, that team usually win."
But Merson feels that, although Arsenal may get the upper hand on this occasion, he doesn’t expect them to get the better over the Blues over the course of the season, adding:
"However, I would be shocked if Arsenal finish above Chelsea come the end of the season."
Arsenal’s sole signing so far this summer - Petr Cech - should make his competitive debut against his former club.
Arsenal have been threatening to mount a title challenge for the last couple of years and the signing of Cech could be the missing piece of the puzzle for the Gunners. But many feel Arsene Wenger's men are still short of a centre-forward and a central midfielder. Some have also called for another centre-back, although those calls are less frequent.
Chelsea, on the other hand, have a squad that needs very little improvement and the Blues will be confident of grabbing a second successive Premier League title for the first time in ten years.