It's funny how football works. Spend over £200m on new players but you still can't defend.Twice in quick succession have Chelsea now conceded three goals, and on both occasions, it happened in embarrassing circumstances.With Edouard Mendy out injured, Frank Lampard chose to play Kepa Arrizabalaga between the sticks but must have been left ruing his decision once more.A calamity involving the Spaniard and Kurt Zouma led to Southampton's second goal at Stamford Bridge on Saturday evening in a piece of play that at this point, wasn't even surprising.The Blues' backline has become a calamity and despite going 3-2 up, the Saints wrestled a draw from the jaws of defeat as Jannik Vestergaard scored a late equaliser.A few weeks ago, Chelsea had come back from three goals down to rescue a point, but this time they were on the opposing end of bad fortune as Ralph Hasenhuttl's men snatched a result.There were a few positives, however. One of them was how the attack clicked, and the second was Timo Werner scoring his first two goals for the club.N'Golo Kante vs SouthamptonHis second was sublime. He turned Jan Bednarek inside out before he raced onto a through ball. The German entered the penalty area and then after stuttering a little bit fired the ball into the back of the net. It was a terrific goal, but unfortunately, he was let down by those behind him. One of the worst individual displays came from midfielder N'Golo Kante.He continuously misplaced passes and looked way off the pace, letting players get the better of him and bringing them down in rather lazy ways. Twitter user @SamardzicFlair took to Twitter to upload the following compilation of his performance - watch the highlights here: 

As you can see, the Frenchman couldn't seem to get anything right. 

Whether it's bringing Kyle Walker-Peters down with an outstretched right-foot or repeatedly playing passes that lacked conviction and power, his display was not one we've become accustomed to seeing. 

During the course of the game, Kante completed just 75.5% of his passes and made no dribbles. That first tally was only better than three other Chelsea players. Meanwhile, he completed just the one tackle and gave away three fouls. 

That final statistic speaks volumes about Kante's play. His average so far this season is only 1.6 fouls per game, while his average pass success is around the 87% mark.

N'Golo Kante vs Southampton

His display against Southampton was far below what we've come to expect from him, but it also goes to show that he's absolutely nowhere near his best.

The trouble for Lampard is that the £63m-rated midfielder hasn't been performing too well for a few years now. 

Kante's average match rating, via WhoScored, has ducked below the rate of 7 in each of the last two seasons - that's something that hadn't happened in his entire career until that point. 

When the Chelsea boss really starts to worry isn't apparent, but he must be thinking of potential alternatives, especially if displays like this become more of a regularity.