If the player you are referring to is Ilkay Gundogan, then you have made a big mistake. Ilkay Gundogan has become an official Barcelona player, it was announced some time ago since Barcelona managed to sign him for free.
Gundogan is very good for tiki taka after about six years with Pep Guardiola at Manchester City. Even Pep upgraded initial tiki taka from Barcelona to Bayern Munich then Manchester City, the core idea of tiki taka was digested by Gundogan. He will not have difficulty in Barcelona especially we saw Xavi did not change the initial tiki taka too much in one season and a half with Barcelona.
I agree that Ilkay Gundogan has contributed greatly to Manchester City's title success over the last few seasons, but unfortunately Manchester City did not manage to extend his contract so Barcelona stepped forward as the next port of Ilkay's career.
They did not want to sign a too long contract with an old player like Gundogan but it is what the player wanted. Without agreement, they had to separated and Gundogan also want to challenge himself at a new league, La Liga.