Facilitating Paul Pogba is the seemingly straight-forward challenge that has troubled Jose Mourinho this season.
Objectively, the solution is clear; play him in a midfield three where two teammates can accommodate his diminished defensive duties. While it is a touch unsettling for United fans that a) Mourinho has not yet realised this, or b) simply chooses not to cater to Pogba's potential, the Portuguese came down on the side of reason today and duly reaped the benefits.
As Manchester United progressed into this year's FA Cup final, Nemanja Matic and Ander Herrera were Pogba's designated carers.
Although question marks over Harry Kane's actual fitness remain, that trio of Pogba, Matic and Herrera proved something of a difference. Practically, Pogba did extremely well to play in Alexis Sanchez for the equaliser, while an intuitive run beyond the attention of Moussa Dembele allowed Herrera to grab the winner.
It was not an outstanding performance, nor did it ever necessarily seem beyond reason that Spurs would pull themselves back into contention. Yet, there remained a crushing kind of inevitability that Pochettino's side would not catch United.
It does not appear so sensational a jump to suggest that Herrera contributed a significant amount to this uncanny sensation. The most dispensable of the three, he has nonetheless captured the imagination this evening.
Ander Herrera puts United ahead! #MUNTOT pic.twitter.com/ZZUiD4UY3O
— Man Utd Goals ? (@UtdGoals) April 21, 2018
Easy to see why so many Manchester United fans love Ander Herrera: will to win, total commitment, passion for the cause, tireless running, and a ruthless finish when it counted. Huge win for #mufc. #FACup semi-final
— Henry Winter (@henrywinter) April 21, 2018
There's not many who truly get what playing for Manchester United means, but Ander Herrera is most certainly one. Must get him tied down to a new contract.
— Liam Canning (@LiamPaulCanning) April 21, 2018
Alexis was excellent, but for me Herrera was the MOTM.
— Nikos Pappas (@nikos1977) April 21, 2018
Alexis played well. Herrera played better.
— Sam Tighe - Ranks FC Podcast (@stighefootball) April 21, 2018
Superb finish from Herrera, who's been on it all day.
Again, some players don't celebrate. Jones looks up to the heavens and heads back into his own half. Valencia does likewise. #mufc
— Samuel Luckhurst (@samuelluckhurst) April 21, 2018
Talk about box to box from Herrera there...
— Michael Cox (@Zonal_Marking) April 21, 2018
Brilliant from Utd, Herrera showing once again he’s a big game player and hugely important to Utd. Superb little player.
— Pilib De Brún (Phil Brown) (@Malachians) April 21, 2018
Pleased for Herrera. Been a difficult season for him with injuries and having to accept a reduced role but has shown up again in a big game. Another good performance from Smalling against Kane, too.
— Rob Dawson (@RobDawsonESPN) April 21, 2018
Unlike Matic and to a greater degree Pogba, Herrera is in possession of a skills set that United could theoretically replace with ease.
Not designed to diminish his talents, it simply appears clear that alongside two specialists, he is something of a reliable nuisance.
With his exuberant displays of affection for the club, his relentless running, and a tendency to act - for use of a better word - like an absolute bollix, the Spaniard offers a manageable degree of menace to United's occasionally placid side.
Ander Herrera is such a snide player and I absolutely love it. Must be so infuriating playing against him.
— Liam Canning (@LiamPaulCanning) April 21, 2018
Ander Herrera. He's a prick, but he's our prick.
— Mike (@mikec60) April 21, 2018
Ander Herrera has had an immense month. I’m not sure what kind of midfielder he is anymore, but I am absolutely here for it.
— Musa Okwonga (@Okwonga) April 21, 2018
Mourinho's reluctance to indulge this three-pronged midfield with greater regularity does perhaps hint at flaws within Herrera's game, rather than any great attempt at stifling Pogba.
After his stunning performance this afternoon, it was not so much his goal that got people excited, but his celebration; he was not so much lauded for his outstanding talent, but his enthusiasm and ability to deliver in United's big games.
This, of course, is no small thing.
In both last year's League Cup and Europa League finals, Herrera played a pivotal role in United winning both; he was named man of the match in their defeat of Ajax.
Furthermore, on a day where he played only his fourteenth full ninety minute game this season a season, four of those previous appearances came against Liverpool, Spurs, Chelsea and Manchester City in the Premier League.
Yet, perhaps it is not coincidental that a League Cup tie with Burton Albion, FA Cup ties against Derby County and Yeovil Town, and three Champions League group stage games make up a healthy portion of the remainder.
The three remaining games include United's disappointing defeat to Huddersfield Town, and two away wins against West Bromwich Albion and Everton.
It hardly screams of a player indispensable to the starting XI.
In possession of something Jose Mourinho clearly likes, it is perhaps Herrera's willingness to tune his natural talents to whatever frequency is required that means he will always have a place - however peripheral - in his manager's plans for a while yet.