Kansas City (5-5-7) at D.C. United (7-8-1), 7:30 p.m.

Washington, D.C. (Sports Network) - D.C. United jumps back into Major League Soccer action on Saturday when it hosts the Kansas City Wizards at RFK Stadium.

The reigning Supporters' Shield winners have played just one MLS match since June 29 - a 2-0 loss to Houston in a makeup game on July 23 - because of the team's participation in the 2008 SuperLiga tournament.

United went 0-3 and was bounced in the group stage of the tourney that features New England and Houston in the final on Tuesday.

Prior to the extended break from league play, United had won four straight and five of six, but since has gone 0-4 in all competitions.

"[United coach] Tommy [Soehn] said we just lost four in a row, which is the first time it's happened in D.C. United history, so no one is really happy about that one," United goalkeeper Zach Wells said after the loss to Houston. "We're not pleased with the way we started the second half of the season. We came out and wanted to get some more points and climb the ladder and just got out-competed I guess."

Part of the reason for the dip in form has been injury problems.

For Saturday's fixture vs. the Wizards, United will be without Ben Olsen (ankle surgery), Marcelo Gallardo (hernia surgery), Santino Quaranta (hamstring strain) and Domenic Mediate (concussion) while Gonzalo Martinez will miss the game because of a red card he received in the loss to Houston.

On Thursday the team did acquire midfielder/defender Ivan Guerrero in a trade with the San Jose Earthquakes for a partial allocation, which should help offset some of the injury concerns.

"We are very excited to have concluded a trade to acquire Ivan," United General Manager Dave Kasper said. "He is an honest and hardworking player who has terrific experience both in MLS and with the national team of Honduras. Ivan is a great fit for our style of play, and we look forward to his contributions to our club."

Kansas City, which is tied with four other teams at the bottom of the Eastern Conference table with 22 points, is steadily improving this season, going unbeaten in its last six league fixtures, although only two of those have been wins.

The strength of the team so far this season has been defense and goalkeeping. Kevin Hartman actually leads the league with seven clean sheets so far this season.

"I think it's really a culmination of a lot of things," Hartman said. "I put in a ton of work in the offseason. I think we've been very, very solid defensively."

"It's something we've worked on and we've talked about since the preseason and clearly it's working," K.C. defender Jimmy Conrad said of the team's defense.

On the other side of the coin, the Wizards have scored just 17 goals in 17 games, better than only the expansion San Jose Earthquakes in the league this season.

"Now it's just a matter of getting a few in the back of the net and getting confident," Conrad added.