Tottenham could have countered the threat of Marouane Fellaini with this one defensive switch.
'Hindsight is a wonderful thing', as the old saying goes, and so Tottenham boss Mauricio Pochettino must have been thinking as he went over his side's disappointing 3-0 loss to Manchester United on the way back to London.
The Argentine had said before the game that he had come to Manchester to win, with United looking vulnerable at times in recent weeks and Spurs strong since their League Cup final defeat to Chelsea. But it was somewhat of a naive move if Pochettino did arrive at the Theatre of Dreams without so much as a consideration for the side Louis van Gaal would put out.
For one thing, he should have noted Marouane Fellaini's increasing influence in attacking areas in recent weeks. The Belgian started in an attacking midfield role against Spurs, and was in dominant form for the home side, causing particular damage with his power and aerial threat.
It was surprising that Mauricio Pochettino didn't consider making at least one switch at the back for the game to counter Fellaini's predictable menace, with Spurs possessing one of the tallest and most powerful central defenders in the league in Federico Fazio.
The 28-year-old hasn't featured domestically since the 3-0 win over West Brom at the end of January, and though Eric Dier has come in and performed well for the most part, it has been surprising to see Fazio ditched just as he was putting in a run of good form alongside Jan Vertonghen.
The Argentine remained on the bench for the League Cup final despite featuring in the 5-3 win on New Year's Day, perhaps his disappointing performances as Spurs crashed out of the Europa League against Fiorentina played a part, with the defender particularly poor in the 2-0 defeat in Florence. But Fazio was always likely to struggle against a side playing to the strengths of Mohamed Salah and his pace, and United didn't have such a weapon with Angel Di Maria suspended.
As it turned out, Fazio wasn't even in the 18-man squad for the match at Old Trafford, something that must have been a tactical move considering there had been no hint that the former Sevilla man was carrying an injury leading up to the fixture.
It will be interesting to see whether the summer recruit from La Liga returns to the starting line-up against Leicester this weekend, given that they too have the option to play to the aerial strengths of striker Leonardo Ulloa, otherwise he may be knocking on his compatriot's door, asking where his next game time is coming from.