Paul Merson believes Chelsea's top-four hopes hinge on their upcoming matches with Manchester United and Tottenham, following the 2-2 draw with Leicester City.
The Blues currently sit four points ahead of Spurs, heading into a crucial run of fixtures where they face Manchester United, Tottenham and Bayern Munich.
Results so far this year have been inconsistent and Lampard made a huge call for the clash against Leicester, dropping Kepa Arrizabalaga and replacing him with Willy Caballero.
Merson has stated that it was the 'biggest decision' of Lampard's managerial career so far and still believes that there is no issue with the goalkeeping options at Stamford Bridge.
"If you had asked me five weeks ago if Chelsea had a problem with their goalkeeper, I would have said no, I thought Kepa was good. He has had a bad time," he told Sky Sports.
"I thought he made a big decision, I think that is one of his biggest decisions since he became a manager in football if I am being honest.
"Caballero made a mistake, which can happen when you change the goalies, but he is a decent person to come in. I know he made a mistake, he is probably too keen and he has not played for a while.
"I am all right with Chelsea at the moment, they have two big games coming up - Man Utd and Tottenham at home - if they win both of them, for me they will finish in the top four.
"You have to remember that it was only a few weeks ago that they were ripping Tottenham to shreds at Tottenham's ground.
"A draw at Leicester is all right. Frank was a bit nervous as they have lost a few tight games this season when they should not have lost. They dominated that game against Leicester for long periods and could have lost it in the end.
"So the next two home games are the ones - if they do not win either of them, I think they are in major trouble for top four. But if they win them, then I think the only ones who can catch them are Wolves."
