One of the benefits of this World Cup is the scheduling. Because of the expanded field, the group stage games are a full week apart, allowing coaches to have something close to a preferred XI without worries of fitness or short turnarounds.
So, hypothetically, if you had two European-based stars in midfield and wanted to play them every second without running them into the ground, that would be possible, right? Do you see where we're going here?
In total, Pochettino brought four central midfielders and, while it seems likely that Sebastian Berhalter and Cristian Roldan will have a part to play, there's no denying that he's leaning heavily on Tyler Adams and Weston McKennie. There's also no denying that those two are worth leaning on. They're both top, top players with the ability to impact the game in ways that complement one another.
So, when you leave players like Tanner Tessmann, Aidan Morris and even Yunus Musah at home, you're saying that this is a team built around Adams and McKennie. There's little cover if that plan goes wrong, and there's little wiggle room for a nightmare scenario that, say, sees one midfielder injured and another suspended.
In truth, there's no surviving a nightmare scenario anyway, so you can see the logic of Pochettino's best as he looks set to roll out his best players as often as possible, particularly in the midfield. Would that have changed, perhaps, if Johnny Cardoso were healthy or if Morris and Tessmann were better in March against elite competition? Maybe, but it's clear that Adams and McKennie have Pochettino's trust.