"In the last four matches, we have one clean sheet," a rather exasperated Thomas Tuchel said after his Chelsea side had been beaten by Everton at a raucous Goodison Park. "And that is the only win [against West Ham United] that we have. So I am very disappointed. We struggle to play without big mistakes. It's why we struggle to have results."
The trip to Goodison was game 58 of what has proved an arduous campaign for Chelsea's staff and players. Bodies are weary. Minds too. It's perhaps why unexplainable errors have become commonplace in recent weeks. Against Real Madrid, it was Edouard Mendy culpable. Andreas Christensen was at fault when Arsenal visited Stamford Bridge. And yesterday, it was the turn of Cesar Azpilicueta.
Over the past decade, Chelsea's club captain has proved himself Mr. Dependable. It's why he's never made fewer than 40 appearances in a season. Right-back or left-back, wing-back or centre-back, Azpilicueta has almost always delivered for the club he joined in 2012 from Marseille.
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"I can't remember in his career when that has happened to him," Chelsea midfielder Ruben Loftus-Cheek said after the 1-0 defeat at Goodison Park. "It is one of those ones, and I am sure he will put it behind him very quickly as we have some big games coming up. Azpi is a fantastic player, and no one will blame anyone."
Whether Azpilicueta should have been selected against Everton is a point of debate. At 32 years old and with more than 700 senior appearances in his legs, it's almost unreasonable to expect the Spaniard to not suffer a drop off in performance, especially given he played 90 minutes against Manchester United on Thursday. The same could be argued over 37-year-old Thiago Silva, although the Brazilian has seemingly defied the ageing process during his two seasons at Stamford Bridge.
Tuchel didn't have Christensen to call upon at Goodison – the Dane has struggled with a stomach issue in recent weeks – and after his rather rash display during the 4-2 defeat to Arsenal, it wasn't a huge surprise to see Malang Sarr confined to the substitutes' bench once more. But what about Trevoh Chalobah, the breakout star of the Blues' campaign?
The 22-year-old has enjoyed a strong debut season in the Chelsea first-team squad. He has made 27 appearances and racked up almost 2000 minutes, the majority of which have come on the right of the back three, the position that Azpilicueta started against Everton.
In March, there was a slight dip in form, a couple of games in which mistakes crept into Chalobah's game. But Tuchel insisted that the academy graduate had rediscovered his focus after that month's international break and that first-team minutes would be afforded in the forthcoming fixtures.
"Trevoh played a lot and has had a very, very good season so far," Tuchel said on April 19. "He had a little dip in form some weeks ago, but for many weeks he is back in full shape in training. We had a talk recently, but I cannot prove [what was said] with minutes and game minutes at the moment. But he is exactly at the level where he was at the beginning of the season.
"It's impressive because he overcame this kind of period where things felt a bit more difficult for him during the winter period. He had some mistakes, and was not as comfortable on the pitch or reliable as he used to be.
"Now he is back to full strength. He just needs to be patient. For me, he is taking it very well and is training excellently. This is what we demand from him. I think he will see it with minutes in the next matches."
Since those comments from Tuchel, four matches have been played. Chalobah has featured in just one: the victory over West Ham. It was the young defender's first outing in over a month, but barring one shaky first-half moment, he was a composed figure on the right of the back three, and Chelsea claimed that clean sheet Tuchel was keen to highlight in the press room at Goodison Park.
Shutouts have become a common theme of Chalobah's debut campaign at Stamford Bridge. He has started 15 top-flight matches under Tuchel, nine of which ended without the Blues' backline being breached. He also started in the 4-0 win over Juventus in the Champions League group stage and helped keep Liverpool at bay over 120 in the Carabao Cup final.
And while not every performance has been a defensive masterclass – for example, the 1-0 win over Brentford in October was very much backs to the wall – it's worth noting that 60 per cent of the clean sheets recorded by Chelsea in the Premier League this term have come with Chalobah in the side.
That does not make the academy graduate a cure-all solution for Tuchel in the battle to finish in the top four ahead of Arsenal and Tottenham – Chalobah remains in the early stage of his Chelsea career, and it's natural there will be peaks and troughs in his performance.
Yet he shouldn't continue to be overlooked by the Blues' head coach, especially given the mistakes of those trusted by the German against Arsenal, Manchester United, and Everton.