I don't actually think the midfield is that stacked. Busquets, De Jong, Nico, Gavi, Pedri realistically are the options. Roberto is more of a utility man and hasn't been deployed as an out and out midfielder for a long time.
Puig, Sanz etc - forget about it.
Busquets is going to be 34, three of them are teenagers that shouldn't be run into the ground and we are then 1 injury away from depletion. Plus even in the Pep era we had the Keita's as well as the Xaviesta's.
He's free, if it doesn't work out, he will have plenty of suitors as he will be 26/27 and we can make money from selling him. Not much to lose, a lot to gain.