Edouard Mendy
The Senegal international started sluggishly and gifted Ivan Toney an opportunity with a poor pass out. Fortunately, the Brentford striker wasn't able to take the opportunity. Mendy did require treatment on an apparent knee injury in the opening period but was able to continue.
After the break, he had to pick the ball out of his net three times in quick succession as Brentford opened up a surprise lead. There was little the Chelsea goalkeeper could do about the three goals as he was left unusually exposed by the Chelsea defenders in front of him. 6
Cesar Azpilicueta
Deployed at right-back, the Chelsea captain was a little more reserved in his attacking runs, although when he did offer an overlap, he rarely got the ball from Hakim Ziyech. Azpilicueta dropped in on the right of a back three after Chelsea had fallen behind and looked more comfortable. But by that point, the Blues were chasing the game. 6
Thiago Silva
Perhaps the most uncomfortable Silva has looked in a Chelsea shirt for a long while. The movement of the Brentford front two, Toney and Bryan Mbeumo, was problematic for the Brazilian, and the Bees were able to drag him out of position when part of a centre-back duo. The Brazilian was more composed in the middle of a three, but the visitors were ahead at that stage of the contest. 5
Antonio Rudiger
After a first-half sighter from the centre-back that drifted wide of David Raya's goal, he finally scored the goal Chelsea supporters had long waited for as a 35-yard drive from Rudiger found the back of the net. Unfortunately, there was very little time to enjoy it as Brentford then struck three times in 12 minutes – and Rudiger was guilty of letting Vitaly Janelt run off him for the Bees' third. He was also at fault for the Bees' fourth late on as he sliced a clearance into the path of Yoane Wissa. 5
Marcos Alonso
He started the game with two poor passes and didn't truly improve from there. He was always ready to get forward and provide an outlet, but attacks tended to break down when he was left in one-on-one situations. Alonso had started to find some form prior to the international break after a poor couple of months. Chelsea will hope this is just a bump in the road ahead of the season run-in. 4
Ruben Loftus-Cheek
In possession, the academy graduate was arguably Chelsea's best performer in the opening 45 minutes, but it was notable that Brentford found it easy to progress into the final third with Loftus-Cheek playing as the number six. The Bees exploited that further in the second half to go ahead after Rudiger's strike. Loftus-Cheek continued to show his on-the-ball quality as the Blues attempted a fightback, but it wasn't enough. 5
Mason Mount
The England international mustered Chelsea's first shot on goal of the afternoon with a whipped effort that went wide. However, he drifted out of the contest from then on, despite no little endeavour. It's still likely that the England international starts in midweek against Real Madrid, but he'll almost certainly be restored to the front three, where his off-the-ball work will likely prove more beneficial. 5
N'Golo Kante
Barring his excellent performance in the Champions League Round of 16-second leg against Lille, Kante has been somewhat out of sorts in 2022. And that continued against Brentford. Used as an eight, the Frenchman had a licence to get forward but very rarely made an impact in the final third. He was also unable to stop the ball across the penalty area for Brentford's second, although he was left in a two-on-one situation. Blues supporters will hope Kante can rediscover his best against Real Madrid. 5
Hakim Ziyech
Spent much of the first half out on the touchline and was restricted from delivering crosses into the penalty area by the Brentford backline. Ziyech had a little bit more joy in the second half and after he was moved onto the left, but he will have wanted to offer a bigger creative threat. 5
Kai Havertz
The German started once more ahead of Romelu Lukaku but struggled to impose himself. There were a couple of neat touches in the opening 45 minutes, but Havertz didn't have any real influence. He did have the ball in the net in the second period as Chelsea attempted to mount a comeback, having conceded three times in quick succession, but the goal was ruled out for handball.
A toe poke from the 22-year-old also went agonisingly wide, and he glanced a header beyond the far post. He tried to get the Blues back into the game and was one of the few who upped his level of performance after Tuchel's side had fallen behind at Stamford Bridge. 6
Timo Werner
This was only the German's fourth Premier League start since the beginning of December. He may not get many more between now and the end of the campaign. Werner was poor in possession in the opening period, and that theme continued after the half-time interval. He had one half-chance but saw his effort blocked. 4
Substitutes
Reece James (for Marcos Alonso, 55)
Introduced shortly after Brentford's second goal, James was sent over to left-back before being moved to right wing-back. Had little impact in either role. 5
Romelu Lukaku (for Timo Werner, 63)
There were a couple of nice lay-offs from the Belgium international, but he didn't have a clear sight of goal, having been sent on to help rescue the game. 5
Mateo Kovacic (for N'Golo Kante, 63)
Much like Lukaku, was charged with hauling Chelsea back into the game but was unable to. 5