Might have been mentioned elsewhere, but a pair of US national team players will be moving to Europe in this window ... one on paper, one in the flesh.
Zack Steffen, recently named USMNT player of the year for 2018, has signed a time loaded agreement with Manchester City that will finalize in July of 2019. In the meantime he stays with the Crew and will be looking to gain a UK work permit. That's something City's expensive lawyers are working on, but look for him to get some more caps for the US during Camp Cupcake in January. The likelihood is high that Steffen will end up being loaned out after he joins City, with speculation running to Spain or the Netherlands. Either would be a step up from MLS, and thus good for his development.
Tyler Adams, formerly of NY Red Bulls, has signed with RB Leipzig of the Bundesliga, reuniting with his former coach Jesse Marsch who is on staff in Leipzig. The clubs are both part of the RasenBallsport franchise, so this is kind of an in house deal. Adams had emerged as one of the better young two-way midfielders in MLS over the last two seasons and is a product of NY Red Bulls Academy, having joined their age group teams at 12 years old. No speculation yet about RBZ loaning him out, so look for Adams to break in slowly for the rest of the European season (mostly in training, I'd think) before they figure out his place in the pecking order. RBZ has been a develop and move outfit, so while their midfield might look crowded now, that could change quickly. This is a big move for Adams and should be well planned out since RB has been his home since he was a child. IMO he's good enough to play European football, but still needs experience.