This competition hasn’t seen the best of the Whites at any stage of his tenure but it has held some promise this season, with a pair of wins taking him into uncharted territory.
The fourth round is the furthest Bielsa has progressed in this competition, or in any knockout tournament for that matter given the winless FA Cup record compiled over his first three seasons.
And while 20 different players were used in the wins over Crewe Alexandra and Fulham to book a trip to the Emirates, both line-ups held a faint suggestion that Bielsa might be giving the Carabao Cup a little more priority this season.
A surprisingly experienced, strong team welcomed the Railwaymen to Elland Road and the XI at Craven Cottage boasted £27m Rodrigo, £25m Daniel James, marquee players Kalvin Phillips and Illan Meslier, along with other first-team regulars.
Mikel Arteta’s Gunners obviously provide stiffer opposition than either of the clubs Leeds have beaten along the way and to progress Bielsa will likely have to go strong again in his selection.
Meslier is expected to start – Wolves troubled him so little on Saturday that he should be fresh and he played in the previous two rounds.
Pascal Struijk and Diego Llorente were partnered against Crewe and this game might allow the former to return to his more natural position of left-sided centre-half alongside the Spaniard, giving Liam Cooper a rest and retaining experience and form in the heart of the Leeds backline.
The fear, of course, with Llorente is that you risk him picking up another niggle but he has looked physically strong of late and the idea of 22-year-old Struijk playing alongside 19-year-old Charlie Cresswell still feels a little on the premature side, even if the England Under 21 defender is a born leader.
Stuart Dallas remains the club’s only fit senior left-back option and having shown a drastic improvement in form against Wolves, in the second half especially, he might benefit from a chance to build up a little more steam.
Jamie Shackleton is in line for a sixth straight start at right-back, with Luke Ayling still recovering from a knee surgery.
In the midfield, Phillips needs minutes and the fact that he did not feature in the Under-23s game last Friday, before joining the squad to give Bielsa an option on the bench, suggests he’s not so far off that he couldn’t handle at least 45 minutes or an hour in the Carabao Cup.
Adam Forshaw should also feature for at least some of the game, as he continues in his attempt to prove he can form part of the solution to Leeds’ midfield issues this season.
Out wide, Bielsa has a range of options. Daniel James is still learning the ropes of Bielsaball and did well in the latter stages of the draw with Wolves, so there’s little to suggest he will come out of the team.
Crysenio Summerville, brave and tenacious against Wolves, could play but Jack Harrison probably needs to play. A poor performance in defence and attack prompted Bielsa to hook the winger at the break on Saturday.
The head coach is on record saying Harrison needs regular football in order to find and maintain form, so it would be no surprise to see him starting.
Similarly Tyler Roberts, desperately in need of a goal or an assist or even just a performance that allows him to puff out his chest and silence his critics, may find himself on League Cup duty up front or in the number 10 role.
Neither Harrison or Roberts played well at Southampton and with Summerville and Joe Gelhardt breathing down their respective necks, must start grasping opportunities.
There is an argument for Rodrigo, who visibly shook off the weight of the world with not only a successful penalty late on at Wolves but his overall performance, to start. Momentum could be key for the club’s record signing, ahead of a vital game at Norwich next weekend.
If the majority of the aforementioned make up the guts of Bielsa’s line-up, it will be another strong statement of intent in this competition but also tacit recognition of the difficulty of any game against Arsenal.
The identity of the opposition provides opportunity as well as adversity, however. Previously Bielsa has said you cannot be certain if a young player is ready for the Premier League until he plays in it and unless Arteta fields his 23s, this game will recreate conditions as close as possible to those of a top flight, without risking three points.
Perhaps then, this game affords Bielsa a chance to look at players like Cody Drameh at right-back. He watched him at Chesterfield during the international break, when Drameh played very well against a tough Italian side, replicating his Leeds 23s form. He stuck around this summer, when the loan options were numerous and attractive, and the feeling around the club was that it could be a big season. To date, a breakthrough has not looked imminent, the form of Shackleton keeping the younger man waiting.
What of Lewis Bate? There is a lot to like about the young midfielder’s start to life under Mark Jackson and he too showed against Italy Under 20s that he can adapt to the different challenges thrown up by a change in the style and level of opponent. He is another who doesn’t appear to be on the cusp of a senior bow, which is hard to understand without seeing what Bielsa does on a daily basis.
That game in Chesterfield also featured the prolific 23s front man Sam Greenwood and he is knocking hard on the door of a first team struggling to score goals. With Roberts unable to find form, an opportunity for the 19-year-old striker is surely approaching.
And then there’s Gelhardt. Six goals in seven Premier League 2 games, an England Under-21 call up, a first team breakthrough and a game-changing impact against Wolves is a body of evidence most managers would find difficult to look past. Confidence is flowing through the teenager, who realised on Saturday that he can terrify experienced top flight defenders and not just his peers. Bielsa will unleash him fully when the time is right but the time might well be now.
It may be a small squad with a big injury list, but selection headaches are still there to be found.