The move is a massive one for Cardoso, who has certainly earned it with his play on the club level. His performances on that side have never been questioned, but he still does have plenty to prove with the USMNT less than a year out from the World Cup.
Despite his star play in La Liga, Cardoso's game has yet to truly translate to the USMNT, where he's not yet won a spot with a signature performance. He's largely been error-prone, headlined by a poor giveaway against Turkey ahead of the Gold Cup, and injuries prevented him from really making a mark on the ensuing tournament.
Playing under Diego Simeone, who hails from Argentina like USMNT boss Mauricio Pochettino, should prove helpful for the midfielder, who will now be learning from two of the game's best managers, both of whom also played at a very high level.