This is not the competition where Leeds United want Marcelo Bielsa to hang his hat and few of these players have been responsible for taking the club to the top of the Championship.
But the division knows now that Bielsa’s model is not finished or infallible.
A bump in the road was always coming, irrespective of Leeds’ searing rise to the top of the table this month – the only question was how long it would take to arrive.
Bielsa felt it in the second round of the Carabao Cup last night, beaten 2-0 by a Preston North End team who played for 60 minutes with 10 men but made too easy work of reaching the third round.
A red card for Ryan Ledson should have sent Preston out but it was Leeds who spent the tie shooting bullets into their own foot.
Round three for Bielsa had a certain appeal, presenting the chance to reacquaint himself with old friends.
What chance Manchester City or Tottenham Hotspur when Preston are paired in the draw tomorrow, the clubs where two of the Argentinian’s more famous disciples reside?
Bielsa hosts Middlesbrough’s Tony Pulis on Friday for this week’s main event, a clash of coaching cultures as first in the Championship meets second at Elland Road, but the League Cup offered him the possibility of a meeting of minds with Pep Guardiola or Mauricio Pochettino.
The natural step for the narrative building around Bielsa would have been a tussle with one of the two men he famously helped to school.
As it is, all eyes are on the league and a gem of a game to come.
So much that Bielsa has touched has turned to gold in the past three weeks but he could feel yesterday’s tie going wrong from the very start: the concession of a penalty in the first minute, the failure to properly exploit Ledson’s foolish foul on Lewis Baker and the mistakes which played into Preston’s composed hands constantly, affording them a two-goal lead at the break.
A shaky Conor Shaughnessy lasted until half-time and was fortunate to survive that long, reopening the debate over the depth of Bielsa’s collection of centre-backs.
The injection of Samuel Saiz’s genius in the second half could only do so much. A first defeat for Bielsa was incoming and on this occasion he was forced to grimace and bear it.
Whatever Preston prepared themselves for – the onslaught Bielsa is striving to perfect or a considered, tactical opening – cannot have matched up with what they encountered.
So much that Bielsa has touched has turned to gold in the past three weeks but he could feel yesterday’s tie going wrong from the very start ...Phil Hay
Their progress through round two was all but confirmed by the break and the tie was 45 seconds old when Louis Moult went down inside United’s box, tripped by Shaughnessy after Stuart Dallas set an early trend with a loose touch near a corner flag.
Daniel Johnson dealt with the penalty by sending Jamal Blackman the wrong way.
Shaughnessy’s availability and mooted potential is one reason by Bielsa has defied calls to sign another centre-back but he was playing for the first time since January, when an ankle injury resulted in surgery, and the tie did not flatter him.
Bielsa called a halt to his night at half-time. Dallas’ start was his first of the season following a minor muscle strain and the rust took hold in an early blitz of all-at-sea, suicidal passing and weak ball retention.
Tom Barkhuizen almost scored a second within moments of Johnson’s penalty, skimming a shot a few feet wide.
Alex Neil sent his front four to swarm around Bielsa’s defence and the flow of passes from the back was unreliable and intermittent.
Jamie Shackleton drew a one-handed save from Chris Maxwell after Dallas fizzed a pass into Preston’s box and Tyler Roberts and Pontus Jansson made nothing of brief half-chances, allowing Preston to sit comfortably on their goal.
Referee Tony Harrington did his bit with a sequence of calls which irked the home crowd and kept North End coming forward.
Bielsa’s usual impassive manner cracked as the half-hour approached, driven to frustration and some choice words by the fractured football he was watching.
But, in the 30th minute, Ledson succumbed to the red mist and felled Baker with a crunching, studs-up tackle which could be heard 50 yards away in the stands.
Harrington went straight for his back pocket and sent Ledson off. It was the helping hand United had been crying out for.
Almost immediately, Preston lost their composure. A weak punch from Maxwell was headed back over him towards an exposed net by Pontus Jansson but Ben Davies got behind the ball and blocked it on the goalline.
Patrick Bamford had a go from 25 yards, forcing a sprawling save from Maxwell, after North End left the striker with time to size the goalkeeper up and Jack Harrison was marginally further away with a rising shot having skipped past two markers in the final minutes of the first half.
In injury-time, though, Baker twice failed to make anything of crossing opportunities from the left wing and Preston stole the ball and countered at pace.
Brandon Barker’s driving run forced a nervous Shaughnessy to retreat and created enough space for the winger to lash a brilliant shot across a helpless Blackman and inside his far post.
It left Bielsa with two options: take the defeat or take drastic action.
Friday’s Championship game against Middlesbrough was at the back of his mind but he refused to lie down, sending for Saiz and Mateusz Klich at the interval.
Saiz’s skill and pace was felt whenever Leeds worked possession to him, but to no avail.
Bamford slashed a shot wide on 47 minutes and a header from Roberts deflected over but there was no killer chance and no goal to set Preston on edge as cross after cross met a visiting head.
The clock ticked down, encouraged by some extreme time-wasting, and an injured Tom Pearce limping through to the final whistle with all three substitutions used encapsulated the extent to which the plan fell apart.
One to forget, in amongst so many games to remember.