Fernandinho probably is going..
So we have Gundogan (31) Debruyne (30) Bernardo and Rodri as a midfielders.
Considering injuries Gundogan and Debruyne had during the last years - it means that midfield area is the most vulnerable zone. Not mentioning the problem - which made pep to start with Bernardo-Gundogan-Debruyne yesterday and sacrificing Sterling to make sure that ball possession and tempo was OK..
And number 9 isn't that vulnerable. Aguero has been missing for whole season and the results are perfect, number of goals team has scored is amazing.. Pep mentioned that he has Jesus, Torress who played their in the first half of the season and showed some good qualities, Delap from the academy - great talent, Sterling - Bernardo - Mahrez and plenty of players who he has used there from time to time.. So Attacking area is well-covered.
Midfield needs improvement and new blood.. Grealish is the perfect candidate for that.