The biggest need here might actually be "left back." While Andy Robertson's attacking output still remains fantastic, he has become a defensive liability. I've written about how athletic players age worse than skilled players, and Robertson certainly seems like an example of the former. It was one thing for him to get cooked by Bukayo Saka for the opening goal in the 1-1 draw with Arsenal; it's another thing to get roasted by Real Madrid's 33-year-old makeshift right back, Lucas Vázquez.

It would seem like the team might want one of these "elbow back" type of players -- the kind of hybrid center back/fullback that pinches in and aids in ball progression instead of bombing down the wing. But (1) left-footed versions of these players are extremely rare, and (2) this would also seem to hinge on whether Trent Alexander-Arnold signs a new contract. So, maybe not the move for January.

Instead, the biggest area in need of improvement in the immediate and long term seems like "holding midfield" depth. Ryan Gravenberch has been a revelation this season, but he has played nearly all of the league minutes thus far, and he has never come close to playing that many minutes yet in his career. Liverpool manager Arne Slot doesn't trust Wataru Endo to play valuable minutes, and the effort to add Real Sociedad's Martín Zubimendi over the summer suggests the clubs see this as an area of need.

To try to identify an option for most teams in the league, we're going to use Michael Imburgio's DAVIES model, which values players based on their age, their role, and the overall value of everything they do with the ball. By looking at each player's statistical profile, the model is also able to separate players into one of 19 different roles. However, there aren't many other players who fit into Gravenberch's role and provide most of their value through dribbling and passing, so perhaps we look for someone in Zubimendi's role instead?

Among players classified as "playmaking deep midfielders" by DAVIES, only a handful of other guys rate better than Stuttgart's 23-year-old Angelo Stiller (valued at €30 million on Transfermarkt). Although they're in the Champions League, Stuttgart are stuck in midtable of the Bundesliga.