Hmm, I'm not sure, it depends how Gomes does.
If we're wanting a player who is more of a ball carrier with an eye for the pass to play next to Gana, then I think Gomes could be just that man - obviously with the caveat that if he stays fit/finds his Valencia form
If we're wanting a deep-lying playmaker who is tough in the tackle, can pick a pass and carry the ball/get about, then someone in the mould of Parades from Zenit would be ideal I reckon.
If we're wanting a big, powerful player to dominate in that area, then perhaps Denis Zakaria, or Kondogbia, or Ndombele (type of players).