The Brazilian, who was confirmed as the winner of the prestigious France Football prize on Monday, was brought down to earth when he was left out of the squad for tonight's Spanish Primera Liga match against Rayo Vallecano.
Van Gaal explained that Rivaldo had said he no longer wanted to play on the left side and favoured a more central role. "Yesterday Rivaldo spoke to me and said he no longer wanted to play on the left. Because of that, he's been left out of the squad," Van Gaal said. "It was a surprise for me and a surprise for his team-mates. It's a great shame. Barcelona has always had the philosophy that the club comes ahead of everyone - the players, the coach and all the employees."
The move is sure to fire further speculation about Rivaldo's future at the club after he was linked with a possible move to Manchester United.
Rivaldo has had his share of problems at Barcelona since his move from Deportivo La Coruna at the start of the 1997-98 season. The Brazilian international complained last season about being stuck out on the left wing, saying he would be used more effectively in the middle. He knuckled down, however, to hit the best form of his life, scoring 24 league goals as Barca romped to the title.
Rivaldo's form has dropped somewhat in recent weeks, though, as a heavy workload at international and club level has taken its toll. He has not scored in the league since October - in a 2-1 defeat by Deportivo - and despite setting up his side's first goal against Atletico Madrid on Sunday he was whistled by fans when was substituted in the second half.
Van Gaal has made a habit of leaving out his main players from time to time, usually without any explanation. In Sunday's game against Atletico, Barcelona took the field without their captain, Josep Guardiola - the first time the Spanish international midfielder had been dropped in his career.