RIO DE JANEIRO, Feb 28 (Reuters) - Brazilian World Cup winner Rivaldo walked out on Cruzeiro on Saturday after less than two months at the club in solidarity with coach Vanderley Luxemburgo who was fired the day before.

"I took the decision overnight," he told reporters in a media conference broadcast on Brazilian television. "I haven't got (another) club, nothing like that. At the moment, I'm being faithful to the coach who brought me here."

Rivaldo failed to settle at the Brazilian champions, who he joined after spending most of the previous 18 months warming the substitutes' bench at Italy's AC Milan.

He played only 10 competitive games for Cruzeiro, who have made an indifferent start to the season, and scored only two goals, both in last weekend's 7-1 win over Mamore.

He was frequently jeered by the Cruzeiro supporters.

Cruzeiro spokesman Valdir Barbosa said the club had accepted Rivaldo's decision even though he had signed a one-year contract when he joined on January 5.

But the episode raises doubts about the future of the 31-year-old former Barcelona, PSV Eindhoven and Deportivo Coruna forward, who has barely played club football since helping Brazil win the World Cup in 2002.

Rivaldo joined Milan immediately after the tournament in Japan and South Korea but barely got a look in and described his spell there as the worst of his career.

He also stands to lose his place in the Brazil team, which he has kept until now despite his lack of club football.

RIVALDO'S MENTOR

Luxemburgo, Rivaldo's mentor earlier in his career, was fired on Friday, barely three months after leading the Belo Horizonte-based club to their first Brazilian championship.

The controversial former Brazil coach, who had been in charge since mid-2002, offered his resignation on Friday morning, changed his mind in the afternoon but was fired when the directors refused to allow him to reconsider.

Rivaldo played under Luxemburgo at Palmeiras in the mid-1990s and in the Brazil team that won the Copa America in 1999.

"I didn't sleep well after Luxemburgo's sacking. When he left, I preferred to leave as well," said Rivaldo. "It was my decision because I consider Luxemburgo to be a special person."

Asked about his poor form since joining the club, Rivaldo said: "A player should be judged at the end of the competition and not at the start, after just a few games. I was happy here, getting better game by game."

By Brian Homewood