The newly-appointed Malaga boss believes the Brazilian will prove to be "another nuisance" in La Liga next season and revealed he came close to taking a role in the Middle East.
The Brazil star joined the Liga champion for 57 million euros last month. Schuster - who took the reins at La Rosaleda after Manuel Pellegrini joined Manchester City - believes the Catalans have invested in "another nuisance" who will make life tough for La Liga's defenders.
"The Confederations Cup is where we really saw him and he began to reach those expectations," Schuster told AS. "Aside from [Lionel] Messi, he is a player who is going to give a lot to Barcelona.
"They are going to win a lot, and complicate things for us. Now we have another nuisance who is going to make life impossible."
Schuster revealed he came close to accepting offers from the Middle East, China and Russia before Malaga approached him to replace Pellegrini, and he is delighted to have returned to Spain.
"Until Malaga came along I saw myself outside of Spain," he explained. "In Turkey, Qatar, Dubai, Russia or China, they were very interested. Luckily, Malaga got in contact and that made me very happy.
"Spain has something special. That is where the national team is, the big teams... in general, La Liga is more competitive and more healthy than elsewhere."