Last season they reached the quarter-finals seeing off Liverpool on penalties and Leicester before losing to eventual champions Manchester City 4-1.
Last season they beat Harrogate Town convincingly before losing to a Brentford side on penalties that were promoted to the Premier League.
With Valerein Ismael as their new coach and three wins out of four in the Championship, they are looking to cause an early upset by sending The Gunners home immediately.
This is usually a game for Arsenal where they have a chance to field a youthful side and give some new names opportunities to stand out, but with their poor form and no wins or goals this season yet, it is uncertain whether Mikel Arteta will take the risk or field a strong side to face the Baggies.
West Brom look set to put out a strong side as they always take cup tournaments very seriously and with Arsenal as their opposition, it's not a match to take easy despite their current record.
They come off the back of a 2-1 win against Blackburn Rovers and a 4-0 hammering against Sheffield United during the week before.
Arsenal however are on the flip side with 0 points in two games, having lost to Brentford and Chelsea by two goals to none and will be looking to get their first competitive win of the season.
The two sides have met four times in the Carabao Cup before with Arsenal winning all four matches.
The last time they faced in the cup in 2013 it went to penalties with The Gunners winning 4-3 from the spot.
Arsenal will be without Ben White (COVID 19), Eddie Nketiah (ankle) and Thomas Partey (ankle). Hector Bellerin (thigh) and Willian (COVID 19) are being monitored closely before the match.
However, there is some good news with Gabriel Martinelli, Alex Runarsson, Gabriel Magalhaes, Kieran Tierney & Alex Lacazette all back in full training and could feature while new signing Martin Ødegaard has been given full clearance and is available for selection.
New signing Aaron Ramsdale looks set to start, and players such as Mohamed Elneny and Nuno Tavares should be given some game time.
Arteta said in the buildup to the game: "We will see. They’ve both been training a few days, only a few days, we just got the VISA from Martin yesterday I think and Aaron has been a while without training, but they both want to play."
At the Hawthorns, Matt Clarke is being assessed ahead of Wednesday after picking up a hamstring injury which means former Arsenal academy man Semi Ajayi should be recalled into the defence.
As for the starting eleven, former West Ham man Grady Diangana could haunt Arsenal's backline but we can expect a similar lineup to the Blackburn match.
Arsenal: Ramsdale, Tavares, Mari, Chambers, Maitland Niles, Xhaka, Elneny, Nelson, Smith Rowe, Pepe, Balogun.
West Brom: Button, Furlong, Bartley, Ajayi, Kipre, Mowatt, Livermore, Phillips, Reach, Diangana, Grant.
Where and when to watch:
The match is at The Hawthorns and kick-off is at 8pm UK, with the match being televised on Sky Sports Main Event or Sky Sports Football.
For the analysis of the game afterwards, check out the Arsenal VAVEL section for more.