Houston, TX (My Sportsbook) - Chicago Fire coach Denis Hamlett has needed to juggle his defense all season, but the team's results don't show it.

Chicago, which lost the SuperLiga final to Mexico's Tigres on Wednesday, has posted four straight shutouts in MLS play.

The Fire (8-3-8) have maintained their consistency in the back despite playing seven different guys, and a different back line in every game in July.

Brandon Prideaux and Bakary Soumare came back into the back four last weekend, helping Chicago to a 1-0 win over Real Salt Lake to start August off right.

Although Hamlett admitted it is "real hard" to drop a match in penalty kicks, the defensive effort was just as impressive against Tigres - which scored its lone goal on its lone shot in the 1-1 tie.

Chicago's defense will be tested again Sunday at the Houston Dynamo (10-6-5), who still have the best record in MLS despite losing three of their last five.

"The guys on the back line are doing a fantastic job," Chicago goalkeeper Jon Busch said. "It hasn't been easy because we have had a new back line almost every game. But guys have stepped up and done a tremendous job."

The Fire lost 1-0 against Houston on June 5, but take an impressive 5-1-4 road record to Robertson Stadium to take on the struggling Dynamo.

Defender Wilman Conde and forward Brian McBride - who is likely done for the rest of the season - will miss this weekend's game, but the Fire were lucky to keep midfielder Cuauhtemoc Blanco and defender Gonzalo Segares.

Blanco will join Mexico for Wednesday's World Cup qualifier against the United States, while Segares will join Costa Rica for qualifying - but after Sunday's match.

Houston will also be at full strength but will lose Brian Ching, Ricardo Clark and Stuart Holden to the U.S. for qualifying after the match.

The Dynamo's struggles - they have just one win in their last five and two in their last eight - continued Thursday in a 1-0 loss to FC Dallas.

"I just don't think we came out to play tonight," said Holden, who scored the lone goal in the first meeting with Chicago..

Houston is 6-1-3 at home, and although the "turnaround is going to be a tough one," goalkeeper Pat Onstad said Thursday, the Dynamo have won four straight against Chicago.

The Dynamo have injury concerns with Eddie Robinson and Richard Mulrooney both out, Brian Mullan doubtful, and Kei Kamara questionable, though. Brad Davis compounded the problems by receiving a red card from the bench Thursday and is suspended for the match against Chicago.