Torreira came off a full season, the world cup, into a team in transition with a new manager and was hot/cold in a new league.
He's a FAR FAR FAR better player than Gana.
This season he'll be ridiculously good. Id swap them in a heartbeat.
Now, as for our own players...
Sigurdsson is a shoe in and i think the majority of posters would agree that he isnt great at CM. He will stay in a somewhat '2nd striker' position.
That leaves us with Gomes and ANother in central midfield.
I really cant see us going for another Gana 'type'.
My view is that there will be 2 types of player we will go for:
1 -- Someone like a Schneiderlin (perhaps Sosa arrives) with top potential. That player can work in our current system and in a 433 system as we evolve.
2 -- A box to box player who is someone like a Sangare (massive) who can also fit into a 433 seamlessly.
I actually think we would sign both of these types if Gana was sold. Dare i say Sosa and Sangare.