Petit's men are undefeated in three matches in all competitions and they will look to extend that streak against an opponent that have not won a game since April.
Match preview
Cuiaba's last league game saw them end Bahia's 100% home record by stunning the second-best side as hosts this term, winning 2-1 last weekend to notch their first top-flight victory in nearly a month.
Isidro Pitta's brace either side of Jean Lucas levelling for Bahia was enough for Dourado to win their fourth Brasileiro match of the campaign.
Petit has made Cuiaba harder to beat since his appointment in May, even if the Portuguese manager hopes his side turns draws into maximum points, underlined by four stalemates in their recent six league fixtures.
The victory over Bahia was followed by a draw in their Copa Sudamericana last 32 first leg with Deyverson levelling for the Brazilian side.
Having won just one league match in front of their supporters under Petit, the hosts are not sure-fire favourites despite facing Fluminense.
The away side have endured a wretched top-flight campaign leaving Fluzao bottom of the table as the midway point of the season approaches.
Fluminense have accrued just eight points after 16 matches, with their only triumph coming in a 2-1 win over Vasco da Gama in April.
Thirteen games have been played since, but there has been no turnaround for last season's Copa Libertadores champions, who have lost a joint-high 10 defeats before this weekend's match.
They hope to take advantage of Sunday night's opponents having an eye on next week's last-32 second-leg match in the Sudamericana keen to build on a couple of draws against Internacional and Criciuma (both 1-1).
A second league victory of the season for Fluminense could take Mano Menezes' team above Atletico Goianiense and possibly Gremio with the pair three points ahead of the bottom club.
Cuiaba Brasileiro form:
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D
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L
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W
Cuiaba form (all competitions):
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L
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D
Fluminense Brasileiro form:
L
L
L
D
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Team News
Cuiaba have no reported injuries before Sunday's match, pointing to an unchanged lineup.
Pitta's brace against Bahia took him to six league goals, three more than Clayson and the forward hopes to add to his tally this weekend.
Fluminense's Jhon Arias is back from Copa America duty but it remains to be seen if Menezes starts the Colombian winger days after the final disappointment.
While German Cano returns from suspension, Vinicius Lima (muscle), Lucas Calegari (ankle), David Terans, Felipe Melo (both have calf injuries), Marcelo and Manoel (both have thigh issues) are unlikely to play.
Cuiaba possible starting lineup:
Walter; Railan, Marllon, Empereur, Ramon; Sobral, Mineiro, Denilson; Cafu, Pitta, Lacerda
Fluminense possible starting lineup:
Fabio; Xavier, Carlos, Santos, Esquerdinha; Martinelli, Andre; Marquinhos, Ganso, Keno; Kennedy