3 reasons why Chelsea's season has gone off track

#1 Defensive frailties

Kurt Zouma and other Chelsea defenders have not impressed this season.

While this season Chelsea have largely impressed with some scintillating attacking football, the defensive side of the game has left a lot to be desired. Even during their winning run, they looked extremely shaky at the back. So far this season, Lampard's men have only kept four clean sheets across all competitions. Only Arsenal (27) have conceded more goals than the West London outfit's 25 in the league.

With Antonio Rudiger's absence, Lampard has been unable to settle on a centre-back pairing. While Fikayo Tomori has been the revelation of the season, he has had a few mistakes in him and neither Andreas Christensen nor Kurt Zouma have impressed. The Blues have conceded a huge number of goals through set-pieces or aerial balls in the box. The inability of Chelsea defenders to win headers has become a huge cause of concern and the absence of a leader in the back-line is more evident than ever.

Making things worse has been goalkeeper Kepa Arrizabalaga, who has looked a shadow of the player he was last year. The Spaniard has the second-lowest save percentage (56%) of any keeper in England's first division and has conceded numerous questionable goals. He has struggled to command the box and even lacked confidence on the ball, which was seen as his biggest strength in his first season at the club.

No team can achieve any sort of success being as vulnerable defensively as Chelsea are. Sorting the problem out is Lampard's biggest managerial test so far and the factor that is going to make or break Chelsea's season.