Anthony Martial's last contribution to Manchester United's season may prove his most important. He was the first of three substitutes to effect a three-point swing in the race for fourth place in the Premier League. Martial found Edinson Cavani who centred for Marcus Rashford's 93rd-minute winner against West Ham last week.
A case of managerial magic? It would seem so. A goal in United's truest traditions? Arguably, given that substitutes, in Teddy Sheringham and Ole Gunnar Solskjaer, won them a Champions League in injury time. A theme of their season? Undeniably. United have eight goals from substitutes in the EPL, the most of anyone.
But also an indictment of their poor planning? Possibly.
Martial's subsequent exit, on loan to Sevilla, felt a consequence of confused recruitment. They had just too many forwards. They had overloaded in attack by bringing in Cristiano Ronaldo and Jadon Sancho last summer. They have no way of keeping all happy, not enough spots on the pitch to satisfy everyone. They have so many talented substitutes there is less of an art to making changes.
With Ronaldo and Bruno Fernandes invariably starting, it had left only two slots for Rashford, Cavani, Martial, Sancho, Mason Greenwood, Jesse Lingard and Juan Mata to contest, even before Anthony Elanga's emergence and the versatility of Paul Pogba and Donny van de Beek are factored in.
Ralf Rangnick may have wanted two players for every position. In the front four, he has three, most of them capable of playing in multiple roles. It explains why two of those displaced by buys are heading for the exit; and yet the marginalised Martial and Lingard may help prevent a season undermined by chaotic thinking from finishing in failure.
West Ham have been beaten by two late goals this season, one that Martial helped make, the other, in London in September, scored by Lingard. Without those, David Moyes' team would be five points ahead of United.
And United are the opposite of their immediate rivals. Moyes has a solitary out-and-out striker, with no cover for Michail Antonio. Tottenham's squad contain only two real goalscorers, in Harry Kane and Son Heung-min. Mikel Arteta took the decision to exile Pierre-Emerick Aubameyang at Arsenal. He can usually hold one of Emile Smith Rowe, Bukayo Saka, Gabriel Martinelli and Martin Odegaard in reserve, but otherwise his bench looks bare when he wants goals and assists.
Meanwhile, Rashford has four goals as a replacement already. United had assists in three Champions League games from substitutes, in Lingard, Greenwood and Fernandes. That can reflect strength in depth and their various managers' capacity to read games and see who and what is required.
Yet when United have stockpiled players to such an absurd degree that van de Beek has played 69 minutes in the league, Lingard 89 and Martial 209 while Cavani, Rashford, Greenwood and Sancho have suffered from Ronaldo's return, their salvation could come from substitutes who were benched because they brought back a superstar without much of a strategy of what to do with every one else.