What Sanchez’s arrival means for Kepa’s future and the battle to be Chelsea’s No 1

Spare a thought for Kepa Arrizabalaga. The world’s most expensive goalkeeper barely had time to congratulate himself on seeing off Edouard Mendy to consolidate Chelsea’s No 1 spot before the London side opted to spend up to £25million ($31.7m) bringing in a fellow Spaniard aiming to leapfrog him for club and country.

You can rest assured that Robert Sanchez has not joined Chelsea to sit happily on the bench — partly because he refused to do so at Brighton and Hove Albion and also because clear-cut back-up goalkeepers are not given seven-year contracts.

So, a battle to be Mauricio Pochettino’s starting goalkeeper looms and, given that Kepa stands as one of the last big Roman Abramovich-era contracts that Todd Boehly and Clearlake Capital have not cleansed from the  books, there will be people within the club hoping Sanchez emerges victorious.

It is even possible that the 25-year-old’s arrival brings forward the end of Kepa’s rollercoaster Chelsea career to this summer’s transfer window.

Bayern Munich are interested in a possible loan deal with an option to buy as Manuel Neuer continues his lengthy rehabilitation from a broken leg sustained last December, while Real Madrid are canvassing the market for available goalkeepers in the wake of Thibaut Courtois rupturing his ACL in training this week.

Kepa leaving Chelsea so close to the start of the new season would throw the entire defensive half of Pochettino’s new team into flux just as he works to remodel his attack in the absence of Christopher Nkunku.

The smoothness of the subsequent goalkeeping transition at Stamford Bridge would depend above all on the answer to a key question: how good is Robert Sanchez?

Prior to the arrival of Roberto De Zerbi he had no shortage of believers at Brighton, where he jumped from fourth choice to starting goalkeeper inside a dizzying few months in 2020-21 and kept the role until losing his place to Jason Steele in March.

One of those admirers was then Brighton boss Graham Potter, who explained his decision to elevate the Spaniard by saying: “If you think there is a player that can play in pretty much any football club in the world, has that potential, then you have to try and give them a pathway to play.”

Another was Ben Roberts, who followed Potter to Chelsea to serve as his goalkeeping coach in September 2022 and has remained at the club in a new, Christophe Lollichon-esque role that encompasses goalkeeper scouting and recruitment as well as coaching across all age groups.

Roberts’ departure from Brighton coincided with the beginning of the dip in form that ultimately cost Sanchez his starting spot. The two are very close and while they are unlikely to be working together on a daily basis at Chelsea — Toni Jimenez is Pochettino’s goalkeeping coach, assisted by Hilario and James Russell — the hope is that Roberts’ intimate knowledge of the Spaniard’s game and mindset can help Chelsea maximise his potential.

That potential is huge, according to The Athletic’s goalkeeping analyst and former professional goalkeeper Matt Pyzdrowski. “There’s a lot he can bring to the table that Chelsea haven’t had in a while in a goalkeeper,” he says of Sanchez. “It’s not a slight on the goalkeepers who have been there in the last couple of years, but Sanchez could bring another dimension.”

Size is a significant part of it. Standing at 1.97m (6ft 6in), Sanchez is slightly taller than Mendy and considerably taller than Kepa 1.89 m (6ft 2in), with a much longer wingspan.

Brighton sought to capitalise on that by instructing him to be aggressive coming off his line to claim high balls delivered from set-pieces and open-play crosses.

Despite one or two embarrassing misjudgments, overall Sanchez was a real asset in this regard — claiming six per cent of the crosses he faced in the Premier League in 2022-23. Kepa claimed just 3.5 per cent of his, and his desire to remain rooted to his goal line contributed to Chelsea’s struggles defending set pieces.

Sanchez signing for Chelsea earlier this month (Photo: Chris Lee – Chelsea FC/Chelsea FC via Getty Images)

But what really excites people in goalkeeping circles about Sanchez is his varied skill set. Promoted by Potter primarily because he was more comfortable and versatile with his feet than Mat Ryan, at different stages of his Brighton career he also impressed as a sweeper-keeper and as a shot stopper from both short and long range.

“He’s got the whole package really,” Pyzdrowski adds. “There aren’t many keepers in the world who have what he has when you look at his size, his fundamentals and his skill set. Kepa doesn’t have that size and reach. We’ve also seen big keepers not have the fundamentals or the ability to use their size, but Sanchez has that really nice combination. The key for him is putting it together.”

Chelsea’s risk in sanctioning this deal is that Sanchez has not consistently put it together yet, and there is no guarantee that he will, despite his tantalising blend of size and skills.

The best advanced metric for assessing a goalkeeper’s core performance is expected goals on target (xGOT), which takes into account factors such as shot placement and angle to quantify the quality of on-target shots that a goalkeeper faces, giving each effort on target a score between zero and one based on how statistically likely that shot is to go in.

A comparison can then be made between the number of goals that a goalkeeper actually concedes with their cumulative xGOT faced, to see how a goalkeeper over or underperforms based on the quality of shots faced. The below graphic illustrates how Sanchez’s xGOT performance fluctuated over the course of his Brighton career:

Sanchez underperformed relative to xGOT in each of his three Premier League seasons as Brighton’s starting goalkeeper, conceding 6.6 goals more than expected overall (-2.5 in 2020-21, -0.3 in 2021-22 and -3.8 in 2022-23). Kepa, in contrast, was the third-best performing goalkeeper in the division by this metric in 2022-23, conceding six goals fewer than expected.

Chelsea have had to endure even wilder shot-stopping extremes during Kepa’s time at the club, however, and the below graphic highlights that he has spent more time under-performing his xGOT than over-performing it at Stamford Bridge — with his individual nadir in the summer of 2020 prompting the purchase of Mendy from Rennes:

It is far from clear whether Sanchez would be able to provide an upgrade on Kepa as a shot stopper. The same can be said for his distribution, which ironically was the reason why Potter favoured him over Ryan and why De Zerbi preferred Steele over him.

“At this moment, he (Steele) is closer to my idea, my style,” De Zerbi said after dropping Sanchez earlier this year. “Robert is improving, but Jason deserves to play. When I speak of my style, I’m speaking about the foot.”

De Zerbi demanded a level of comfort on the ball and appetite for risk in baiting the opposition press from his goalkeeper that he did not feel Sanchez could provide. The Spaniard is adept at hitting short and medium range passes, but he is not Alisson or Ederson in terms of his technical mastery. Neither is Kepa, whose kicking under pressure was a source of frustration for Pochettino at times during Chelsea’s pre-season tour of the U.S.

Goalkeeper distribution is inevitably conditioned by the style of the team and the coach’s instructions. In the below graphic you can see that a higher proportion of Sanchez’s passes last season were directed short into central areas, in accordance with De Zerbi’s style:

Kepa, meanwhile, more often clipped the ball out to the flanks in 2022-23:

Pochettino will not ask his goalkeepers to do precisely the same things on the ball as De Zerbi. But even accounting for this, the numbers indicate Kepa is more accurate with his distribution; he completed 81.7 per cent of his passes despite hitting 47 per cent long, while Sanchez’s pass completion was 70.2 per cent despite hitting a lower proportion (35.2 per cent) long.

All of this suggests that installing Sanchez as Chelsea’s No 1 goalkeeper now or in the near future would be more of a leap of faith than a decision backed by empirical evidence. Even signing him at all is a bet on what he could be, rather than what he has been so far. But it is clear that Roberts trusts the evidence of his eyes, and so does Pyzdrowski.

“Sanchez has higher upside than Kepa,” he insists. “He really is a complete goalkeeper. Is he perfect? No, but when you look at everything he brings to the table with his feet, with his positioning, with his ability to claim balls in the air, his traditional shot stopping and 1v1s, he’s very, very good.

“I like him a lot. I don’t rave about goalkeepers in this way too often, but there’s something about him — regardless of the stats — when you watch him play.

“I love the way he moves, I love his confidence, I love his aura, and to get all those intangibles with the size and the fundamentals… he has what a lot of goalkeepers will never have. The key is for him to put it all together and live up to that potential.”

(Top photo: Robbie Jay Barratt – AMA/Getty Images)