It's going to sound weird but United's fall off this season with regards to their set-piece threat for me is one of their two biggest reasons for their sudden downturn in form. It's a very subtle detail in recruitment and methodology that has had a proper domino effect. Casemiro goes and you're thinking how do we replace his defensive contributions (because he's a defensive midfielder) or improve on his in-possession quality (with Carrick preferring small-space, more fluid, principle-based combinations). This explains the signing of Tielemans, Baleba and Santos. You get small space, technical footballers to evolve the game model, to be passy, and draw in pressure before then playing long, quickly to the fast attackers. Tielemans and Santos go here. Baleba gives you the legs and coverage as an alternative – in a way that a younger Casemiro might. For me, Casemiro's biggest strength and it was an outsized strength in a huge way, was his ability to score from set-plays. Great defender at set-pieces too, to be fair. United under Carrick, even when their form was good, struggled to break down defensive blocks, especially when they were given the majority of the possession. They thrived in transition, attacking big space. Casemiro gave United, even when they lacked the consistent open play solutions against deep defences, a clear way to break them open. More possession would lead to more set-plays which would lead to more Casemiro/Bruno inspired goals. From a winning game state, it becomes acceptable to sit in and counter. Opponents also spend more time on the ball trying to get back in the game. This game state suits United's players, they play to their strengths and win more. It's a bit like Gabriel at Arsenal over the last few years, who at times struggled to break down blocks in open play but because they had such a good attacking set-piece threat, long possessions that gifted them set-plas became valuable. They were then able to build a team that was stronger defensively, and required less risk in settled attackers. United were able to skew their side towards one that counter-attacked well with less open-play risk/solutions because they had reliable set-play solutions. Part personnel, but also the loss of Amorim's set-piece guy is one that is deeply felt too. United had some of the best set-piece numbers across the last season, in the world. Not replacing Casemiro, or the set-piece brains, in the summer has genuinely flipped the form of their squad for me. The other big issue is that the 4-2-4 block has sort of been solved by opponents and United haven't adapted loads.