Sao Paulo: Veteran striker Romario was suspended for 120 days on Tuesday for failing a doping test in a Brazilian league match two months ago.
Members of Brazil's top sports tribunal voted 3-2 to suspend Romario after he tested positive for the banned substance finasteride following Vasco's 2-2 draw against Palmeiras on October 28.
Vasco lawyers said they will appeal.
The 41-year-old Romario, who did not attend the hearing in Rio de Janeiro, claimed he had been using a medicine to prevent hair loss. Finasteride is the active ingredient in the anti-balding medication Propecia.
Vasco lawyers showed a video with highlights from Romario's career, including when he scored his 1,000th goal, and said that the tribunal needed to take the player's past in consideration before making their decision.
Romario was found guilty of violating Article 244 of the Brazilian Sports Justice Code, which bans doping and carries a penalty of suspension for 120 to 360 days.
In a similar case, Internacional defender Marcao was found guilty earlier this year of using finasteride, allegedly to prevent hair loss, and also was suspended for 120 days, but half his sentence was converted into distributing food baskets for the needy after an appeal.
Finasteride is on the World Anti-Doping Agency's banned list because it can mask use of anabolic steroids.
A longer suspension could have prompted the end of a brilliant career for the striker who was selected FIFA's Player of the Year in 1994, the year he led Brazil to its fourth World Cup title.
He has scored 929 career goals by FIFA's count - or 1,000 including goals scored as an amateur and in nonofficial games. Only three other players have reportedly reached the 1,000-goal mark.
Romario's coaching contract with Vasco will last through a tournament next month in Dubai, in the United Arab Emirates, and could be extended through the Guanabara Cup, the first half of the Rio de Janeiro state tournament.