Frank Lampard has already shown himself to be a fairly pragmatic manager. The Englishman won't be getting too carried away with Chelsea's extraordinary comeback from 4-1 down to draw 4-4 with Ajax. It might have been better, had Cesar Azpilicueta's goal not been ruled out. It might have been worse had the visitors not had both their centre-backs sent off. As impressive Chelsea were in the second half, Lampard will want to know how they got themselves into that position in the first place. This brings us neatly to Marcos Alonso. 

Before their latest collapse, Ajax's pace and precision might have exposed even a more consistent left-back. 

Alonso patently struggled. Two of the Dutch champions' goals came from his side and it was telling that Chelsea only started to get back into the game once he was hauled off at half-time. 

Incidentally, replacing him with Reece James, the 19-year-old who became the club's youngest ever goalscorer in the Champions League, was one of Lampard's most inspired moves yet. 

Azpilicueta moved over to the left and showed his capabilities going forward, getting on the scoresheet even apart from his disallowed strike. 

The same couldn't be said of Alonso. A Chelsea fan has compiled a video of his disasterclass and it really is something to behold:

James' highlights can also be seen below. The difference is staggering.

Alonso has not taken his opportunity to usurp Emerson Palmieri as the Blues' first choice.

The Italian was the clear favourite in the pecking order at the start of the season before suffering an injury on international duty. 

While Alonso initially impressed in attack with two assists and the winner against Newcastle, he has since been found out once again. 

Against Manchester United in the League Cup, he gave the ball away 23 times - significantly more than any other player on the pitch. 

The fact he lasted just 45 minutes on Tuesday night said it all - and who can blame Chelsea fans for being exasperated?