Schuster last week hit out at Barca over their treatment of Ronaldinho and ex-Nou Camp hero Rivaldo joined the German in condemning the culture at the club.
Now with AEK Athens, Rivaldo told DiarioSport: "I do not know very well what is happening, but Ronaldo left after one year at Barca. Romario also failed to comply with his contract. I ended up at Milan.
"All players have ups and downs and we went through good and bad times, but I make one thing very clear: Ronnie is the same. Sure.
"Furthermore, I do not think that it is good for the image of Barca that this is happening to Ronnie ...
"In my view everyone must show more affection to Ronie, from the players, to the club and the press.
"It's dangerous what is happening. If people treat Ronaldinho like this when he is out of form, then what can Lionel Messi be thinking when the same thing happens to him?"