It was an experiment consigned to the 'dustbin' after seven minutes, but that was enough time for Ralf Rangnick and Manchester United to offer clear indication as to where one of their transfer priorities lay.
No matter how this season has unfolded, key figures in the Old Trafford boardroom were, for once, due credit last summer when they issued a triple statement of intent.
Jadon Sancho, Raphael Varane and Cristiano Ronaldo marks a staggering window for any club on the planet.
At first glance, it was comparable to the work done by Paris Saint-Germain with Lionel Messi among those rocking up at the Parc des Princes.
However, while the seven-time Ballon d'Or winner followed Italian goalkeeper Gianluigi Donnarumma, jet-heeled right-back Achraf Hakimi, Nuno Mendes, Sergio Ramos and Gini Wijnaldium, that 'cover all bases' approach was not replicated at Old Trafford - and it proved rather costly.
Before his sacking, Ole Gunnar Solskjaer was understood to be frustrated by the club's failure to land a top defensive midfielder and that position remains THE elephant in the room.
Given how much United had spent on Sancho in particular, signing Declan Rice for £100million-plus was always going to prove difficult during the same window and, as such, there are plans to readdress that situation.
It proved too late for Solskjaer to continue his building process, and whoever steps into the dugout to replace him permanently will reap the benefits of previous business.
Kieran Trippier was the other man that got away last summer.
In that case, it was not merely the cost, more how much value he would represent at 31 for £25million.
Fast forward seven months and, in reality, the answer is quite a lot.
Resisting any temptation to revisit him as a target in January, the England defender has come and gone and it was Saudi-backed Newcastle who took advantage with a £12million bargain.
You get the sense, though, that had Rangnick stepped into the breach sooner, he might have asked kindly for that payment to have been made from Old Trafford and not St James' Park to the Wanda Metropolitano.
Incidentally, it was at that fearsome stadium where United proved they are not satisfied with their current options in that position.
Diogo Dalot had been one of the biggest winners since Rangnick took charge.
Indeed, the Portuguese has emerged as first choice there, while Aaron Wan-Bissaka played against Leeds. Despite being available, though, both men were overlooked against Trippier's former club Atletico Madrid.
In any case, had United snapped up the England international he wouldn't have been eligible to meet the reigning La Liga champions and old employers on account of him representing them in the Champions League group-stages earlier this campaign.
Victor Lindelof got the nod in an unfamiliar role last night.
Considering the pre-match comments made by Rangnick, him being able to double up as a third centre-back was justified at a venue renowned for hostility against opponents who challenge anyone physically. Ultimately, though, that call also proved telling on his thoughts towards Dalot and Wan-Bissaka moving forward.
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Tactically it might have made sense, but coupled up with indecision and question marks over that position shows United will almost certainly be on the lookout for a Trippier alternative next season, certainly if Rangnick is the one making those decisions, whether that's from the touchline or sitting behind a desk.
Dalot and Wan-Bissaka will be looking over their shoulder.
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