I'd definitely keep Gueye as an impact substitute. He's too limited to be a regular starter but he can change games, he's very useful in our own box too if we're under the cosh.
We probably won't have the money to bring in anyone significantly better than what we've got, so it'll likely be a case of rotating Ohashi, Gueye, plus a new signing depending on who's in form. Same for the attacking midfielders behind. Thankfully we have a solid defence and central midfield to give us a consistent foundation to work from.