New England (10-13-9, 39 points) trails the Philadelphia Union by three points for the final spot in the Eastern Conference playoffs with two matches left to play.
However, the Revolution know the last-place Fire (6-16-10, 28 pts.) will be playing for pride in front of their fans at Toyota Park in their home finale in Bridgeview, Ill.
"We're going in to almost play spoiler on their home game," Revs midfielder Kelyn Rowe told reporters Wednesday. "For us, it's a huge game because it's on us to prove that we're a playoff team, and we need these three points."
New England is seeking its fourth consecutive MLS Cup Playoffs berth, and a win Sunday would go a long way heading into their season finale against the Montreal Impact on Oct. 23.
The Fire have proven to be a beatable opponent for the Revolution, who have won all three meetings this season (two in MLS play). Chicago leads the all-time series 22-21-11.
The last time New England beat an opponent four times in a single year was 2005, when it went 4-2-0 against Chicago. The Revs haven't swept a four-match season series since 1999.
Chicago erased a 1-0 deficit to earn 2-2 draw with Columbus at home Thursday, eliminating the Crew from the playoffs. It hopes to deal another serious blow to the Revolution on Sunday.
"The people who come, our crowd, our supporters, they suffered too much and we have to give that last game everything we have to win the game," Fire coach Veljko Paunovic said after Thursday's match.
"Everyone has their own goals. Columbus had their own goals. New England has their own goals. They will approach things the way we can't control. We only control what we can do."
A little more rest has been afforded to New England, which hasn't seen the pitch since a 3-1 victory over Sporting Kansas City on Oct. 1, the fourth win in its last five matches.
The Revs may have the services of midfielder Gerson Koffie and defender Jose Goncalves back, as both practiced this week after missing a combined five matches with ankle injuries.