The Gunners were seconds away from a hard-fought win over the champions at the Etihad on Sunday, only for John Stones's scrappy 98th-minute leveller to salvage a 2-2 draw against Mikel Arteta's 10 men.
Nevertheless, Arsenal remain unbeaten in all tournaments this season thanks to their four-goal thriller with City, and the Gunners now turn their attention to a competition that they have not won since 1993.
Here, Sports Mole rounds up all of Arsenal's latest injury and suspension news ahead of their clash with Bolton, who have already eliminated Mansfield Town and Shrewsbury Town from the competition.
David Raya
Status: Minor doubt
Type of injury: Knee/leg
Possible return date: September 25 (vs. Bolton)
Following the thriller with Man City, David Raya was seen limping past reporters in the mixed zone with a bandage on his knee, rendering the Spaniard doubtful for the midweek affair.
Riccardo Calafiori
Status: Major doubt
Type of injury: Unspecified
Possible return date: September 25 (vs. Bolton)
After scoring a stunning equaliser on his first Premier League start, Riccardo Calafiori had to be forcibly withdrawn in the second half against Man City with an unspecified issue - which very well may have just been cramp - but it would be a surprise to see him risked for this one.
Jurrien Timber
Status: Minor doubt
Type of injury: Cramp
Possible return date: September 25 (vs. Bolton)
Arsenal's third new defensive injury concern, Jurrien Timber suffered from cramp in the dying embers of Sunday's game, although it would be a surprise to see the Dutchman's minor issue rule him out of contention for Wednesday.
Martin Odegaard
Status: Out
Type of injury: Ankle
Possible return date: Unknown
Despite being initially cryptic over the severity of Martin Odegaard's ankle injury, Arteta has now confirmed that the Norway international will be sidelined for "a while", although he is keeping his fingers crossed that it will be weeks rather than months before he is seen again.
Mikel Merino
Status: Out
Type of injury: Shoulder
Possible return date: October 27 (vs. Liverpool)
Odegaard's fellow midfielder Mikel Merino is also in the treatment room for the long term after suffering a freak shoulder injury in his first training session, and a return before the end of October is unlikely.
Takehiro Tomiyasu
Status: Out
Type of injury: Knee
Possible return date: Unknown
The injury-riddled Takehiro Tomiyasu is still working his way back from a severe knee injury sustained in pre-season, and Arteta is unsure when the Japan international will be able to take to the field again.
Kieran Tierney
Status: Out
Type of injury: Hamstring
Possible return date: Unknown
Likewise, Kieran Tierney - who maybe could have anticipated a start on Wednesday - is still on the mend from the hamstring issue he suffered at the Euros, with no timeframe on his return either.
Oleksandr Zinchenko
Status: Major doubt
Type of injury: Calf
Possible return date: September 25 (vs. Bolton)
Oleksandr Zinchenko has been missing from Arsenal's last three squads with a calf problem, and there has been no update on the Ukrainian's condition since he first sustained the issue, meaning that an appearance on Wednesday is highly unlikely.
ARSENAL'S SUSPENSION LIST
Leandro Trossard
Return date: September 28 (vs. Leicester City)
While on a yellow card, Leandro Trossard foolishly kicked the ball away after conceding a free kick, leading to his dismissal for a second bookable offence. However, as red cards count across all competitions, he will only miss this game before returning for the Premier League clash with Leicester City at the weekend.
In addition to Trossard, on-loan Bournemouth goalkeeper Neto is cup-tied for the match, potentially handing Arteta a major dilemma in between the posts.