He looks the perfect replacement for when Gana goes
Why would we try to replace Gana with a like for like player? Building a team for continuous relegation fight?
As good as Gana might be, good and successful teams don't have room for a player with his profile.
Gana is useful for Everton as long as Everton set up a team to have less than 40% possession. As he is mostly useful when the opponent controls the ball and the match.
If Everton ever are going to have any kind of success in the future, they must get in players that are better in possession. By increasing possession, we won't need a destroyer type on the midfield.
Fulham is a good example. Palhinha was fantastic for them, but it was very difficult for them to get a balanced midfield with him. After selling him to Bayern Munich he was replaced by Sander Berge. A "worse" midfielder for a third of the money. But better on the ball, quicker, covers more ground and better next to the midfielders they had in the club. Fulham became a better team by "downgrading" their midfield. They had more possession, took more points and goals against was down 15%.
By all means, play Gana when he is available and needed. But looking for a like for like replacement is madness.