Gundogan is still great and will regain his form. We don't need prime Xavi, we need a solid and creative player.
Gundogan hasn't been great though. He is still struggling to regain his past form and it shows, specially on his movement and defensive contributions which are not at the level he used to play before. I wouldn't be too eager to chase Gundogan right now.
Choices aren't great right now, so in a sense it is good Barca will have some time still to evaluate. Gundogan still has too many question marks. Pjanic is having a very poor season with Roma. Favorites of mine Verratti and Koke are pipe dreams as of this moment. Pogba is going to be crazy expensive.
Team is going to have to do serious work in their preparations and planning for midfield though. In house options don't exactly make you excited. Iniesta will be 31 soon and looks to be slowing down, he also has an injury history. Rakitic is not without flaws and might be actually more suited to a versatile premiere utility midfielder. Xavi will leave sooner than later. Rafinha might improve but hasn't really set the world on fire. Roberto hasn't impressed. A lot of people like Denis Suarez at Sevilla, but I'm not overly impressed. They have their work cut out for them.