The Blues are looking to return to winning ways against their title rivals at Wembley with a place in the FA Cup final up for grabs.
Chelsea were beaten 2-0 by Manchester United at Old Trafford last weekend to lose their second game in four Premier League outings.
The west London side are only four points ahead of second-placed Tottenham Hotspur after Mauricio Pochettino’s side were 4-0 winners against Bournemouth.
Former Arsenal midfielder Merson believes there is a lot at stake in the context of the title race when Chelsea take on Tottenham in the FA Cup.
“Looking at this match from a psychological point of view in terms of the title race, it’s bigger for Chelsea than Tottenham,” Merson told Sky Sports.
“If they lose this after the defeat at Manchester United, then the doubts will really start creeping in.”
Chelsea are looking to win their second Premier League title in three season.
Antonio Conte was appointed as Guus Hiddink’s permanent successor at the end of the 2015-16 campaign.
The Blues are looking to win their first FA Cup crown since a 2-1 win against Liverpool in 2012.
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news