Corinthians striker Jo was fined for wearing green shoes - the color of rival Palmeiras.
The 34-year-old former Manchester City, Everton and Brazil forward wore light green boots in Sunday's 0-0 draw to Bahia.
The club said that its directors "spoke with Joe about using the shoes in the match against Bahia this Sunday. The player was warned, fined and would not wear them again, neither Not in training nor in sports."
The two So Paulo clubs share one of the fiercest rivalries of Brazilian football and Joe apologized to Corinthians fans for what he called "an unnecessary brawl" over the shoes he said were "turquoise blue".
"I will never use green shoes because of my history with the Corinthians, a club I used to love," he said in a statement published online by the news magazine Veja.
"I would never disrespect the Corinthians, not the fans at all. I have always respected this shirt and I will always respect it."