The Blues begin a new month with an away trip against one of last season's promoted sides, and we have the key stats and information you need ahead of the game...
Watford vs Chelsea head to head
This is the third time we have conceded five goals or fewer after 13 Premier League games - all other teams have done so only three times between them.
In 2020/21, we lost all three of our Premier League away matches in December, against Everton, Wolves and Arsenal.
Chelsea are hoping to end a run of five consecutive Premier League games on a Wednesday without a win (three defeats, two draws).
If selected, Reece James will reach two landmarks against Watford - his 100th appearance for Chelsea in all competitions as well as his 50th Premier League start.
If fit, Mateo Kovacic will make his 100th Premier League appearance.
Championship - second
FA Cup - third round
Carabao Cup - third round
Top scorer all competitions: Ismaila Sarr 13 (all league)
Most starts: Sarr 12, Cathcart, Dennis, Sissoko, Troost-Ekong all 11
Most assists: Dennis 5, Femenia 2, King 2
Most clean sheets: None
Red cards: Kucka 1
Dennis 5, King 5 (1 pen), Sarr 5, Hernandez 1, Kucka 1, Pedro 1
Only Norwich (one) have scored the opening goal in fewer Premier League games than Watford this season (three). The Hornets have gone on to win all three games in which they have scored first.
Claudio Ranieri’s six Premier League games in charge of Watford have so far seen 25 goals scored (11 for, 14 against), the most in a manager’s first six games in charge of a club since Frank Lampard at Chelsea (also 25).
Although Watford have failed to score in a seven of their 13 Premier League games this season, only seven sides have scored more goals than Watford (18) in the competition.
No side has conceded more Premier League goals from outside the box than Watford this season (five), while all 18 of the Hornets’ goals have been from inside the box.
Claudio Ranieri has won one of his seven Premier League games against sides he has previously managed (two draws, four defeats), beating Chelsea 2-1 in December 2015 when he was with Leicester.
Watford are unbeaten at home in their last four Premier League matches in December, winning the last two against Man Utd (2-0) and Aston Villa (3-0).
The Hornets have committed more fouls than any other Premier League side this term (181).
Claudio Ranieri’s managerial record against Chelsea:
There are no suspensions.
In the Premier League, five yellow cards received before 19 league fixtures have been played will result in a one-match-suspension in the competition.
Premier League bookings list
Watford: Dennis 6 (already served a suspension), Etebo 3, Cathcart 2, King 2, Kucka 2, Rose 2, Sissoko 2, Troost-Ekong 2, Femenia 1, Louza 1, Pedro 1, Sarr 1, Sema 1
Referee and VAR
VAR: Darren England
David Coote’s last Chelsea game was our 5-2 home defeat against West Brom in April.