It seems that İlkay Gündoğan has no intention of going anywhere. Galatasaray wanted him very much, but after yesterday's game he made a statement that I have a contract for one more season and I'm very happy here. I believe I have a few more years at the top level, he said, which shows that he doesn't want to leave the Top 5 leagues.
If Manchester City decide to let him go again, his new club will be at least as strong as Barca. I don't think he will go to Galatasaray and I don't think City will give him to other Premier League teams either. He may struggle to keep up with the pace, but he still has a lot to offer. He didn't miss a game last season.
Gundogan is very grateful to Pep for giving him the opportunity to play in City. He has won most of the teophies with City and he believes he deserves more. He does not see Galatasaray as a club matches his status and that will make him still stay in City. However, I doubt that Barcelona will take him back when his contract expires with City.