The Bees narrowly beat Colchester United 1-0 in the second round of the tournament on August 28, while the visitors overcame Millwall 1-0 on August 27th to progress to this stage of the competition.
Match preview
Thomas Frank's Brentford will be hoping they can bounce back from their 2-1 defeat on September 14th last time out against Manchester City.
Frank's side took the lead after just one minute thanks to a goal from Yoane Wissa, and though Erling Haaland scored twice in the first half to give City all three points, opposition manager Pep Guardiola was full of praise for the Bees' performance in the first 45 minutes.
Brentford had 52% possession, produced five shots on target and generated more xG than Guardiola's team in the first half, and though they were outplayed by City in the second period, few teams have troubled the champions at the Etihad to the extent that Frank's side did.
Brentford are currently ninth in the Premier League with six points after four matchweeks, and if they were to progress from the third round of the EFL Cup on Tuesday, they would surpass last season's showing in the tournament.
The Bees had 72% possession against Colchester in the second round and limited them to just one shot in the first half but were fortunate to have not conceded considering Jack Payne missed a penalty in the 82nd minute.
Frank's team come into the clash having won three of their last four competitive matches, and having lost just one of their last eight games at home, winning three times and drawing on four occasions.
The visitors edged their most recent match against Reading 1-0 on September 14th, a game in which they failed to create a single big chance, but they limited their opponents to just one big chance of their own.
However, Leyton Orient's league campaign has been poor so far given the club are third last in 22nd place with just three points after five matchweeks.
After the O's win against Reading, boss Richie Wellens suggested that his side's game management and decision making still needed to improve, but insisted that his team are a "work in progress" and that they would "keep getting better".
Leyton Orient have been eliminated from seven of their last 11 ties in the EFL Cup, and were knocked out by Plymouth Argyle last term on August 8th after they lost 2-0 in the first round of the competition.
Wellens's team have lost five of their eight competitive fixtures so far this season, including two of their last three, and have lost two and won two of their four away games in 2024-25.
Brentford EFL Cup form:
W
Brentford form (all competitions):
Leyton Orient EFL Cup form:
W
W
Leyton Orient form (all competitions):
L
L
W
L
L
W
Team News
Brentford will be without Gustavo Nunes and Mathias Jensen until sometime next month, while Igor Thiago is unlikely to feature until December.
Joshua Da Silva could return later in the year, while Aaron Hickey and Rico Henry are also not expected to make an appearance on Tuesday.
As for the visitors, centre-back Daniel Happe was substituted in the 70th minute due to injury, and he is not likely to make an appearance.
Leyton Orient could name a similar XI to the one that beat Millwall in the previous round of the competition, with the likes of Lewis Warrington, Darren Pratley and Zech Obiero candidates to start in midfield.
Brentford possible starting lineup:
Valdimarsson; Trevitt, Van den Berg, Mee, Janelt; Yarmoliuk, Onyeka; Damsgaard, Carvalho, Lewis-Potter; Schade
Leyton Orient possible starting lineup:
Hemming; James, Beckles, Cooper, Sweeney; Pratley, Warrington, Obiero; Agyei, Jaiyesimi, Perkins
We say: Brentford 3-1 Leyton Orient
If Brentford are able to replicate their first-half performance against Manchester City on Tuesday, then they should be clear favourites to progress.