The Brazilian side were knocked out by Argentine outfit River Plate in a controversial game, with the referee escorted from the pitch by riot police after awarding a last-minute penalty that saw the home side lose on penalites.
However, they may now be given a reprieve, with CONMEBOL sowing doubt over the prospect of the first 'Superclasico' final, between River and Buenos Aires rivals Boca Juniors.
In an announcement on Thursday, the governing body confirmed the first leg of the final would take place with Boca as the home team, but is yet to reveal the venue for the second leg. Gremio have appealed after it emereged that River's manager flouted a touchline ban.
Marcelo Gallardo was banned from the fiery second leg, but has now admitted to being in the dressing room at half-time, and communcating with his staff during the game.
"I took that audacity because I thought the players needed it and I needed it too," Gallardo said.
"I broke a rule, I recognise and take responsibility, but it is what I needed and I don't regret it."
If Gremio are successful, then they would take their place in the final, meaning Boca would face a trip to Porto Alegre rather than a short journey across the Argentine capital.
"The first final of the CONMEBOL Copa Libertadores 2018 will be played on Saturday 10 [November], at 16:00 local time, at the Boca Juniors club stadium. The second final will be played on Saturday 24, also from 16:00 [local time]," CONMEBOL said in their statement.
1 November 2018