Given how much money is at stake such a coach would probably cost pocket change and if it gives you any kind of advantage, why not? It's easy to imagine that some micro management before a sub might unlock a few percent, even if it's only for a few minutes.
I think it's about those first few minutes especialy. If a player has had a poor preparation prior to being subbed in, their first couple of minutes on the pitch will take that role - meaning that, as you say, you're missing some percentage of their full potential performance for the duration of that period (they're basically doing an in-match warm-up). Especially with late-match impact subs, that would be a great waste of intention opportunity.
'Cold players come on and can't do what they're brought on to do because they had an ineffective warm-up' doesn't seem like some great never before realized insight to me.
Having a specialized coach to get them to complete their warm-up seems like something one of the other existing coaches can do, as well.
Yeah, it does sound obvious; but then if you read the quotes, it does seem players need more support to ensure their warm-up is adequate physically and mentally. So it looks to me like there really is a (surprising) gap.
I also mentioned that a fitness coach could probably do a lot of this, but the mental side is also important, there might be some specifically relevant aspects of the game (like penalty kicks), and...
As for the topic at hand, I think it makes sense. I think while they mention "by getting players, technically, physically and mentally ready to enter the field of play and enhance the team" is important, one of the most fundamental things is ensuring they're tactically prepared. I don't care too much about body language, but it's important that they're not only tactically aware of how to approach the game, but also about how the other team are playing. When you're put on with a specific goal (scoring or not conceding) it's very useful to have any gaps, system weaknesses or specific danger routes etc that have be exploited or nullified, some players are brilliant at working these things out while watching the game, others not so much. They of course will be given this information by coaches, but having someone specifically their to watch the game in preparation for bringing a player on with a certain amount of time to influence the game in some manner is useful, and they can have more of a specific view rather than the manager are headcoaches who'll have to be more holistic. For a specialised substitution coach I'd prefer more on the side of tactical analysis and intervention rather than simpler stuff like intensity of warm up and body languague (though I fully accept they play a role).
...this point about tactics is important as well. Clubs have specialists for each one of those aspects already, so maybe you'd need someone who knows these things in general and can bring that all together in the moment (with input fromt he specialists and manager) and then get that across to the sub to tailor his preparations accordingly. An assistant coach maybe? Those are at the match but I imagine would be able to get off the bench and work with subs on this stuff.
Given the vast sums of cash at stake it does make sense to employ specialty coaches to manage such things as ensuring the subs coming are in fact properly fit the moment they come on.
We know about Carrick and McKenna, but in total how many people do United have on staff who are properly considered coaches? Not medical staff, but truly coaching staff. To state the obvious, we look a very poorly coached squad.
And maybe that's something where this kind of people could help out. (Although I really do not want to make this about United's coaching setup specifically. That stuff is all over the forum already. Let's keep this discussion more high-level here.)
Quotes in the OP don’t reflect well on Rashford and Sancho. These are highly paid professional athletes. Do clubs really need to hire someone to make sure they’re a bit more… well… professional?
Seems to be a real football thing too. This needing to he constantly babysat. There are athletes who play amateur sports who seem more capable of making sure they get all these minor details correct.
I debated whether I should include those, since I don't want to make this United-specific. In any case, what I'm thinking is that this is probably pretty common for players - also because it is natural to want to watch the match, especially something like the final of the Euros. But it will be hard to both see what's happening on the field and do a focused warm-up at the proper level of intensity.
