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.
I believe that it is fair for Guardiola to keep Gundogan because he deserves to stay. Remember that Gundogan was given away to Barcelona and when things went sour in the Manchester city camp, he was called back and he didn't hesitate. So, I believe that this is the time for City to honour him and not let him go again to another club. He isn't young and has severally proved his loyalty to the club.