The Foxes travel to Old Trafford for the evening kick-off on Saturday (5.30pm) looking to stop the United juggernaught.
The Red Devils have won both of their Premier League fixtures 4-0, easily brushing aside Swansea and West Ham.
Merson thinks United will have a tougher test this time around though.
And despite their dominant performances in the first two weeks of the season the former Arsenal star is refusing to get carried away by Jose Mourinho’s side.
“I’m not on the Manchester United bandwagon at the moment”
He told Sky Sports: “I’m not on the Manchester United bandwagon at the moment.
“They didn’t look like scoring against West Ham for 25 minutes, and they were far from convincing against Swansea until their late flurry of goals.
“Leicester, meanwhile, have started the season well.
“They will be dangerous against a United side that are obliged to attack at Old Trafford.
“I see them putting up a real fight, but United should overpower Leicester in the end.
“2-1 win for Manchester United.”