After failing to secure an exit from Camp Nou during the summer transfer window, Messi has contributed just two goals and one assist during his opening five appearances of the season.
However, ahead of their highly-anticipated showdown with Los Blancos, Rivaldo feels that the 33-year-old has an opportunity to prove his commitment to the Catalan giants.
Speaking to Betfair, the Brazilian said: "El Clasico on Saturday is the perfect opportunity for Lionel Messi to prove he is still committed to Barcelona.
"He had a tough summer, and has not started the season brilliantly, but this is the perfect match to raise his game and prove that he's still an exceptional player. A match-winning display against Madrid would boost his confidence for the remainder of the season."
Barcelona head into the game sitting in 10th position in the La Liga standings, three points behind Real with a game in hand. body check tags ::