CDM: Lucas Torreira (Arsenal)
One of the signings of the summer, Lucas Torreira has become one of Unai Emery's most important players at Arsenal. The Uruguayan took some time to get settled at the Emirates and has made 19 league appearances this season, scoring 2 goals and providing 2 assists.
But that's not why Emery made the 22-year-old Arsenal's most expensive signing of the summer. Torreira has added some much-needed bite to the Gunners' midfield, usually alongside Xhaka or Guendouzi. His aggressive and combative style of play is integral to Emery's tactics.
CDM: Fernandinho (Manchester City)
Manchester City's over-dependence on Fernandinho was evident in their recent losses to Chelsea, Crystal Palace, and Leicester, but the fact that City are still only seven points behind Liverpool is an indicator of how good he's been this season.
The extraordinary ease with which Guardiola coped in the absence of Kevin De Bruyne was a testament to City's incredible squad depth, but the fact is, they don't really have anyone who can fill Fernandinho's shoes right now. The Brazilian will turn 34 next May but has managed to carry on his brilliant form from City's record-breaking 17/18 season.
Guardiola played John Stones in midfield against Palace due to an injury to Fernandinho, an experiment that spectacularly blew up in his face. Pep's first priority in January will have to be a long-term heir in holding midfield to maintain the pressure on high-flying Liverpool.
CAM: Bernardo Silva (Manchester City)
David Silva has arguably been as good as, if not better than, his Portuguese teammate this season, but Bernardo gets my vote because of how well he has adapted to his new central midfield role.
Silva was a prolific right winger in Leonardo Jardim's 4-4-2 system at Monaco, and he was initially signed to provide quality and squad depth out wide. Thanks to De Bruyne's knee issues this season, Guardiola has shifted him to central midfield, and the 24-year-old has effortlessly filled the Belgian's shoes.
He has 5 goals and 4 assists from 17 starts in the league this season. In fact, he's been so good that he might even keep De Bruyne out of the squad when he returns.