With his Group H-leading team already assured of a last-16 place at the FIFA World Cup, Belgium coach Marc Wilmots is expected to give some of his stars a rest.
Mirallas came off the bench in Belgium's 1-0 win over Russia, while Dembele started the 2-1 victory against Algeria but was substituted.
Everton forward Mirallas, who struck the post with a free-kick against Russia, hopes he gets an opportunity at the Arena Corinthians in Sao Paulo.
"I hope so. We'll see. The coach will change a few players and hopefully I will start," he said.
"I feel no particular pressure. I feel good but we'll see."
Dembele said he was unfazed by who his team would face in the round of 16, with a clash against Germany potentially awaiting if Belgium finish second in the group.
The Tottenham midfielder said Wilmots' team had the confidence to overcome anyone.
"Germany have a good reputation but for us, we don't care who we play," Dembele said.
"I think we have the confidence to say that we can beat any team."
Porto midfielder Steven Defour is another hoping for a starting XI place and the 26-year-old talked up the strength of Belgium's squad.
"We have a lot of quality in our team. Our team is stronger than 11 players. We will see on Thursday," he said.
