Jorge Sampaoli's men find themselves fifth in the table at this embryonic stage of the season, while their visitors are marginally better off in fourth place thanks to a three-game winning sequence.
Flamengo's defence of their Copa Libertadores crown has been a far-from-straightforward affair in the group stage, but the Brazilian behemoths put one foot firmly in the last 16 with a 2-1 triumph over section leaders Racing Club in Group A on Thursday.
Strikes from Wesley and Victor Hugo either side of the half-time whistle cancelled out a Matias Rojas response for the Argentinians, and Flamengo simply need to avoid defeat against basement side Aucas on the sixth and final matchday to punch their ticket to the knockout stages.
Continental matters take a backseat for the time being, though, as Flamengo aim to prolong their pleasing run of domestic results, having knocked Fluminense out of the Copa do Brasil last 16 2-0 on aggregate before a 4-1 thumping of relegation-threatened Vasco da Gama in the top flight last time out.
Humbling their 19th-placed foes with four first-half goals, Flamengo cemented themselves in fifth place with 16 points from their nine games this season, just one worse off than their upcoming opponents and five adrift of early pacesetters Botafogo.
With a three-game winning run and nine-match unbeaten streak in all competitions to protect, Sampaoli's men have made the net ripple in 15 of their last 16 contests across all tournaments while conceding just four goals at home in the 2023 Brasileiro, but their visitors are sure to make the most of their extended period of rest.
With no continental football on the menu this term, Gremio - who only returned to the big time for the 2023 season - have taken the first steps towards returning to either Libertadores or Copa Sudamericana territory next season, and a spot in the group stage of the former will be theirs if they can maintain their current standing.
Following a trident of successes over Internacional, Athletico Paranaense and Cruzeiro - the latter of which saw them progress to the quarters of the Copa do Brasil 2-1 on aggregate - Renato Portaluppi's side hosted Sao Paulo in Brasileiro action last weekend, where they were forced to do it the hard way to triumph.
Jonathan Calleri headed home the opening goal with 15 minutes gone, but Franco Cristaldo and Reinaldo turned the game on its head to ensure that Gremio would cement their place in the top four ahead of matchday 10.
While Portaluppi's side have shown a knack for finishing chances, they conceded at least once in all three of their recent top-flight victories and have just two clean sheets to their name from their opening nine affairs, and their alarming run without a Brasileiro shutout on the road stretches back to September 2021.
Prior to Gremio's relegation from the top division in 2021, the Tricolor departed with a pair of eye-catching results to their name against Flamengo - winning 1-0 away before a 2-2 draw at home two years ago - but the former represents their sole success from their last 11 tries against the reigning South American champions.
Despite their unrelenting schedule, Flamengo boss Sampaoli has nearly all of his options available to him, barring a trio of injury absentees in Marinho (muscle), Gabriel Moga (knee) and Matheuzinho (leg) - none of whom should return for the weekend - while forward Gabriel Barbosa has been absent for unexplained reasons lately.
Sampaoli made just one alteration in midweek from the side that put four past Vasco da Gama, but with fewer than 72 hours to recuperate from their continental exertions, more changes could be in the offing here.
Hugo, Matheus Franca and Everton can all provide fresh legs in the wide areas, while Arturo Vidal and Erick Pulgar will miss out as they prepare to represent Chile in their upcoming international fixtures.
Speaking of household names, Gremio possess two of them in Brazilian right-back Fabio and striker Luis Suarez, but both men were withdrawn with injuries during the second half of their win over Sao Paulo last weekend.
Suarez was able to take part in training this week, but he departed early following pain in his leg and is now touch-and-go for Sunday's match, while Fabio is certain to miss out alongside Reinaldo, who is suspended for an accumulation of bookings.
Joao Pedro and Cuiabano should deputise for their colleagues out wide, while Everton Galdino could be deployed up front if Suarez does not make the cut, and Rodrigo Ferreira (muscle) Diego Souza (knee), Jhonata Robert (ACL), Pedro Geromel (knee) and Pepe (thigh) are also missing due to injury.
Flamengo possible starting lineup:
Cunha; Wesley, Luiz, Bruno, Lucas; Franca, Maia, Gerson, Everton; De Arrascaeta, Pedro
Gremio possible starting lineup:
Grando; Kannemann, Alves, Uvini; Pedro, Carballo, Villasanti, Cuiabano; Bitello, Cristaldo; Suarez
We say: Flamengo 1-1 Gremio
Given their plethora of fresh concerns and perennial defensive concerns on the road, no sheets should be clean on Gremio's side this week, but the in-form visitors boast the much fresher set of legs.
Sampaoli is still blessed with options for change, but Flamengo's Copa Libertadores exploits will likely catch up to them, and both teams' winning streak could be brought to a halt in a tense draw.
For data analysis of the most likely results, scorelines and more for this match please click here.