We already purchased the best CM in Germany, his injury was a freak one from training that looks to be ahead of schedule. Real Madrid and Barca are the only 2 teams stocked in that position but with Madrid not buying Pogba they won't be selling since they have a ban coming up.
In a Pep 4-1-4-1 Fernandinho or Gündogan(Aleix Garcia should be groomed for this role) can be that 1 in front of the defense with KDB/Silva apart of the 4 with Sterling/Nolito Sané/Navas on the wings.
4-3-3. Fernando/Fernandinho/Gündogan in the middle with Delph/Yaya (Garcia's if we ever need to get this far) as options
Point is, we aren't as short a lot of people seem to think. The problem with the MF was Pelle's tactical suicicde playing Dinho/Yaya where Yaya isn't tackling well and Dinho overcommiting to make up + seemingly always a card away from being sent off. That changes the way tackles went in from there. With a more pressure based tactic,with the entire team working to win the ball back as soon as possible, these mistakes shouldn't happen.