Honestly I am seeing three big clubs making great transfers, Fener getting Rossi, Trabzon gettign Trezeguet, Besiktas getting Weghorst or however it's spelled. These are all 10+ million euro valuated players and that will definitely make a big difference, when you have such a high priced player (nearly 200 million Turkish lira) then it must be quite amazing to know that you are solid for that position unless something changes.
But, Galatasaray hasn't done anything yet, they are seriously just "waiting" if you ask me. They should be doing something already, we are in July and teams already started their friendlies at this stage, if you are not ready already, it's going to be tough to be ready later on.
Galatasaray makes their transfers a little slower, since there are changes in the club, primarily in the management, it seems normal to me that they make these transfers more slowly.
A 4-year contract was signed with Sergio Oliveria, whose testimonial is in Porto. A transfer fee of 3 million Euros was paid. I heard that Okan Buruk wanted Sergio Oliveria, right now the midfield is given priority in Transfers.