Antonio Conte made big changes from the side which thrashed Manchester United 4-0 on Sunday for the trip across the capital.
And Merson reckons that was the wrong call.
WEST HAM UNITED
He told Sky Sports: “I’m surprised they went out of the EFL Cup in the manner they did.
“They missed a trick there”
Chelsea manager Antonio Conte got it wrong against West Ham according to Paul Merson
“They’re playing once a week and should have highlighted that as a must-win competition.
“They missed a trick there.”
Chelsea head to Southampton on Sunday and Merse can’t separate the teams.
“Southampton have only lost one in their last 10 and this is a really difficult match for Chelsea.
“Claude Puel’s side will put up a real fight on Sunday because they are extremely difficult to break down and a threat going forward.
“I’m picking a draw but if Chelsea do manage to get a win at St Mary’s, you need to put them back up as contenders.”