BRIDGEVIEW, Ill. -- The Chicago Fire came up short in the Lamar Hunt U.S. Open Cup and their chances of a postseason are creeping closer to impossible.

If there is some sort of consolation prize with three games to go, the Fire do have the opportunity to win the Brimstone Cup when they host FC Dallas on Wednesday at Toyota Park. The Brimstone has been in Dallas' hands since 2002.

"The rivalry's been there from the beginning, and the Brimstone Cup is there. But more than anything for us, we're playing at home," Fire interim head coach Frank Klopas said. "Now we have three games left and we need to win these matches to give ourselves an opportunity to be in the playoffs."

If the Fire (7-8-16, 37 points) win out, that would put them at 46 points. Currently the New York Red Bulls and Houston Dynamo are positioned at the final two wild card spots with 43 points apiece with two games to play.

Chicago needs to win out just to give itself a legitimate chance.

"This last month or so, we've termed this as our playoffs," Fire forward Patrick Nyarko said. "That's how we go into every game now. We know there's no room for error and we're just going all out. It's now or never."

The Fire have not lost a regular-season match since their 2-0 defeat at the San Jose Earthquakes on Sept. 10. Chicago is 3-0-1 since then.

"It just stinks that it came together rather late," Nyarko said. "We have all the confidence now, and we're hoping to win out and see what happens in the playoff push. If not, we can definitely build for next year."

The Fire played Dallas (13-11-7, 40 points) to a 1-1 draw on the road on March 19 when Carlos de los Cobos was at the helm as head coach. Chicago's Diego Chaves had the game's first goal in the 17th minute, but Dallas' Milton Rodriguez equalized in the 19th as neither team could find the goal the rest of the way.

The Fire are coming off a 2-0 loss to Seattle Sounders FC in the U.S. Open Cup last Tuesday in Seattle. Chicago spent the bulk of the match trying to fend off the Sounders while creating very little on the offensive side.

"We tried to attack and they did a great job of swarming us and basically trying to get us out of rhythm," Nyarko said. "We couldn't get great looks or touches on the ball. Anytime you looked up there were green jerseys surrounding you. We also rushed into a lot of things, trying to get the ball off our foot quickly. It's extremely tough to go out there to try and get a win."

"I don't want to use excuses, but the turf did affect us a little bit," Klopas said. "The weight of the passes is a little bit different. Our movement was a little bit different. It was wet. We just couldn't get going."

The situation on Wednesday will be much more to the Fire's liking, playing on grass again and in front of their own supporters.

Chicago has finally established itself home-field advantage, something that hadn't existed in recent years. The Fire are 5-2-8 at Toyota Park this year and are in the midst of a four-game home winning streak spanning their Aug. 21 win over Toronto FC through their Sept. 25 victory against the New England Revolution.

Chicago's home points total this year through 15 games (23 points) is an improvement over their 2010 (4-4-7, 19 points) and 2009 (5-4-6, 21 points) seasons at Toyota Park.

International impact:
Klopas said late last week that the Fire would be without midfielder Marco Pappa, who is playing for Guatemala on Tuesday night against Belize. While Pappa is scheduled to return to Chicago on Wednesday, the combination of a late international match Tuesday night and the travel makes it unlikely that he will suit up.

As for Dallas scoring leader Brek Shea, even though he has put in some work with the U.S. National Team, FC Dallas confirmed that Shea is flying from New York to Chicago to rejoin the team in time for Wednesday's match against the Fire.

Whether Shea will factor into the game remains to be seen. Between Saturday's 90-minute effort during a 1-0 win over Honduras and Tuesday night's match against Ecuador in Harrison, N.J., Shea has had quite a bit on his plate.