Just don't need him. Doesn't play Fern's position for starters.
Then we have Gundogan, De Bruyne, Silva, arguably Bernardo and Foden fighting it out for 2 spots. All signing him would do is eat into Foden's playing time.
He's class and maybe there's an argument for him taking Gundogans spot but I'd rather stick with Ilkay hoping he can get back to his form when we beat Barca 3-1.