Agent Alexander Bursac, speaking to AD on Saturday, revealed Reis has permission to fly to Spain to speak with Barca.
A fee rising to €7.7m has been agreed between the two clubs.
“The clubs are agreed. We'll hear this weekend or Monday when we fly to Barcelona to complete the transfer," said Bursac.
“We want the head coach to see himself at work. So that he gets an impression of his level, and whether he is able to succeed with Barcelona. Quite apart from his footballing qualities: also with regard to his mentality, everything indicates that Ludo can go a long way. He is calm, intelligent and has both feet on the ground."