The Turkey international was targeted by Gala, though appears set to stay with Inter despite Turkey's market not closing until September 12.
"Hakan was a player we really wanted," he told Now Spor. "He's a big Galatasaray fan. He made a big statement about making a big sacrifice in the future. We made another attempt last week, but Inter said they weren't willing to sell him. They said they would if we offered a much higher price than usual. We made an attempt.
"İlkay (Gundogan) sacrificed his salary, and Hakan would have done the same, but his club had very high expectations. If Inter had sold him to us, we would have had to spend 40-45 million. He's a very important player. That's why his deal was difficult for us.
"There was another attempt last week," the coach continued. "Hakan also made sacrifices. But Inter said they didn't want to go through with the transfer. The reason the transfer didn't happen is because Inter didn't want to sell him, and I don't think anything will change."