Fluminense midfielder Deco is set to be handed his first start of the Brazilian Serie A season Sunday when the club returns to the Maracana stadium against Vasco da Gama.
Deco has not been named in Abel Braga's starting line-up since April when he tested positive to the banned diuretic furosemide after a Rio state championship match, reports Xinhua.
The 35-year-old was cleared to return last month after a doping panel accepted that traces of the substance had unwittingly been added to a vitamin supplement prescribed by his doctor.
Having regained full fitness, Deco was used in Braga's preferred formation during training at Laranjeiras Thursday.
Despite his likely return against Vasco, Deco has been told he faces a doping retrial this month after prosecutors appealed the original decision.
Under Brazil's strict drug code, the former Portugal international faces a two-year ban if found guilty.
Sunday's match will be the first Brazilian top-flight fixture at the Maracana since World Cup redevelopment work began at the venue in August 2010.
