You might be away from home and holding the Premier League leaders to a point, but replacing forwards with holding midfielders is not the most popular thing you can do when managing Manchester United.
The problem that faced Erik ten Hag, though, was that not only was the forward in question - big-money summer signing from Ajax, Antony - offering very, very little, the Dutchman's Red Devils' midfield was getting completely overrun.
Thomas Partey and Granit Xhaka are having the seasons of their lives for the Gunners - even if the more glamourous players in the squad are stealing the plaudits - and against Man United on Sunday, they once again put in another assured performance.
With Martin Odegaard - arguably the most in-form player in the Premier League at the moment - working with them in a more attacking central midfield position, the trio dominated the match at the Emirates, with United reduced to hitting Arsenal on the break or testing Aaron Ramsdale from set-pieces.
In fairness to Man United and Ten Hag - who would have been kept up at night trying to devise a way to get the better of this trio even if he did have Casemiro to call upon - he lost his five-time Champions League-winning holding midfielder to suspension in the match before the Arsenal clash, a draw with Crystal Palace, and so began the really hard work.
Ten Hag gave little away in the build-up to the Arsenal game other than he had something up his sleeve.
"We have a plan," explained the Man United boss. "I think we have a good plan, like against Man City, sometimes you have to surprise the opponent. We spoke about it, I have given the instructions, trained them, now we have to deliver."
He also discussed the role Scott Mctominay would play in this plan. "We think he can fill in very well," added Ten Hag. "We have a special role for him and I hope it will work, a little bit like last time."
Whether Ten Hag had spent extra time working with McTominay in training on what he wanted to see from him against Arsenal remains to be seen - the Dutchman may have just been attempting to boost the midfielder's confidence ahead of such a big game.
But what played out showed how heavily reliant Man United now are on Casemiro.
McTominay was at sixes and sevens throughout the Arsenal game, with only one positive moment of note; in the first half he fired a controlled shot at Ramsdale, testing the Englishman.
Aside from that, the game passed him by - he misplaced passes and failed to break up play effectively - and Ten Hag would have almost certainly hauled him off had he an adequate replacement.
Of course, the Man United boss did have Fred on the bench, but he deduced that despite there being 20 minutes left of a match in which there was everything to play for, the Red Devils needed a second player in centre midfield, and so McTominay stayed on.
United were being completely overrun by the Gunners and Ten Hag was left with little choice but to replace the ineffective Antony for his compatriot Fred, rather than another attacking player in, perhaps, Alejandro Garnacho.
Fred's introduction certainly helped United shore up their midfield, at least initially, but as Ten Hag could see, Arsenal were in the ascendancy and even his methods to prevent the inevitable could do no such thing.
The Gunners' winner was far from their best goal of the afternoon, with a just-about onside Eddie Nketiah netting his second of the contest with just minutes left to play, but it was their most important.
In reflection, Ten Hag's "special" plan fell short. McTominay is not yet capable of stepping into Casemiro's shoes and having to do so in such a challenging game cost the Red Devils.
But Ten Hag managed the situation at United, in which he had very little time to prepare for, in the best way possible and there is no doubt that despite this setback, the Red Devils are moving very steadily in the right direction.
