Currently, the Bees sit just one place and one point below the Blues, who occupy sixth position in the Premier League table.
Brentford are on a six-match unbeaten run
With 10 goals scored and nine conceded, there have been more goals in Chelsea's league games than for any other team in 2026/27, a fact that's unlikely to amuse Alonso.
Though only Brighton have outscored them, rock-bottom Coventry, Ipswich Town and Crystal Palace are the only clubs to have conceded more.
In fact, in the calendar year, only the Eagles have conceded more away goals (23) than Chelsea's 21, so defensive solidity is clearly an area to be worked on by the Spaniard and his backroom team.
With Brentford on a six-match unbeaten run and the visitors having only won one of their last half-dozen games away from Stamford Bridge, the hosts are in with more than a puncher's chance of upsetting the odds.
Chelsea haven't lost the last five H2Hs
Indeed, two previous occasions in 2023 are the only times that the Bees have been on a longer unbeaten streak in the Premier League.
10 draws in their last 14 Premier League matches stretching back to last season is also one of those statistics which could be considered both positive and negative depending on how you want to frame it.
It is worth pointing out that Chelsea haven't lost in the last five head-to-head matches (W2, D3) after losing three of the first five meetings in the top flight (W1, D1), with the last four played at the GTech Community Stadium all ending in draws.
The Bees haven't actually beaten their local rivals at home in the Premier League (five games), so what better time for Keith Andrews and his squad to reverse that particular run of form.
Could Henderson play against his old employers?
Jordan Henderson might well get the opportunity to play against his former team if Moises Caicedo isn't considered fit enough to return from injury, but the ex-Brentford captain might find the going difficult against the combative presence of Mamadou Sangare.
The summer signing has certainly proved that he can handle the physical nature of the Premier League after having joined from Lens, and to date, he has already made 127 high-intensity pressures in the opposition half and completed 13 tackles, the joint-fifth highest in the top flight this season.
Henderson is still a fearsome competitor who gives his all, but with the greatest respect, he's no longer in the same league as his colleague Caicedo.
The Ecuadorian is rated as having a reasonable chance of making the game, and unless he appears to be really struggling, Alonso will surely take a gamble on the 24-year-old.
Both he and Henderson, along with Emmanuel Emegha, will face late fitness tests, but Marco Palestra is definitely out for the visitors.
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Joao Pedro is key for Chelsea
One player who is certain to play, and who Chelsea will be relying on to shoot them to glory, is Joao Pedro.
The striker already has six goal involvements this season (three goals and three assists), and since the beginning of 2025/26, no other Premier League player has both scored and assisted in a match on more occasions than the Brazilian's six.
It was also his goal that ultimately earned his side a point in their last game, a disappointing 2-2 draw at Stamford Bridge to new boys Hull City.
For the Bees, Joshua Dasilva, Antoni Milambo, Nathan Collins, Kaye Furo and Sepp van den Berg have been ruled out, with Mathias Jensen only given a 25% chance of making the game.
Two contrasting styles
There's likely to be two contrasting styles on show on Friday.
Andrews will likely set Brentford up in a defensive shape, making them difficult to play against, and they'll look to hit Chelsea on the break.
Alonso, meanwhile, will almost certainly expect to see the free-flowing, attacking football that the Blues have become synonymous with over the past few seasons.
With no more league games to play after this one before the first international games of the season, a win here will ensure the victors go into the break with their tails up, and that confidence can't be overstated.