Last Sunday, ex-D.C. Christian Gomez and Facundo Erpen orchestrated a 2-0 defeat in Colorado.

On Thursday, former United defender Brandon Prideaux returned in Chicago Fire red and helped smother United in another 2-0 setback.

Prideaux departed after the 2006 season, Erpen followed him to Colorado during the 2007 season. A major clearout last winter stripped away Gomez and several other central components of a team that posted the league's best regular-season record (16-7-7) but lost to Chicago, 3-2, on aggregate in the Eastern Conference semifinals.

That defeat marked the third straight season D.C. had failed to reach MLS Cup and must have convinced Coach Tom Soehn and club management their team was broken, since they ruthlessly began fixing it.

Or so they thought. Its record (2-5-0) is bad enough; it has conceded 14 goals while scoring nine for a goal difference of minus 5. Last year, it was plus 22.

Soccer clubs, like those of most team sports, must be strong down the middle, and so far, United's new spine is frighteningly fragile.

United didn't think Brian Carroll had the legs or spirit to anchor its midfield anymore, so he left in the expansion draft. On Thursday, Clyde Simms and Rod Dyachenko couldn't stabilize the middle of the field against Chicago, and it was Simms trailing in Cuauhtemoc Blanco's wake as Blanco sauntered forth to crash home the clinching goal. (In Columbus, Carroll and the Crew are 5-1.)

Bobby Boswell won the 2006 MLS Defender of the Year Award but a rough start to the 2007 season moved him to the bench. He and Soehn, in his first year at the helm, never did repair their relationship and during the offseason Boswell went to Houston in a trade.

As poor as some of his displays were last year, the United back line isn't any better.

D.C. signed South American imports Gonzalo Peralta and Gonzalo Martinez to reform the back line but it has yet to stabilize. Soehn has used both three-man and four-man systems, with Marc Burch often the swing man between left mid and left back.

Bryan Namoff still has his game, but miscommunication has been rampant. Nobody reacted in time Thursday when Chad Barrett headed down a cross that Peralta challenged in the air. The ball ran free into the middle of the penalty area where Justin Mapp had only to choose his corner and sidefoot the ball past keeper Zach Wells.

Simms or Dyachenko should have been tracking Mapp from midfield and Martinez had the responsibility to slide over when Peralta left the middle to duel for the cross. Mapp may have scored anyway but certainly he should have been forced to shoot through a scything, desperation tackle, at least.

Last Sunday, Gomez broke open a 0-0 game by spinning free in the middle of the field and playing a perfectly weighted diagonal ball that Jacob Peterson crashed first-time high into top corner. As the ball ran to Peterson, Martinez slid over to close him down but didn't so much as a raise a foot to block the shot that ultimately decided the game.

Gomez isn't the same caliber as United's Designated Player Marcelo Gallardo, but in their head-to-head meeting, his MLS experience showed. Gomez darted about the midfield in sharp bursts, not the languid 'S' routes preferred by Gallardo.

He knows when to go with the flow and when to jam on the accelerator and when to forget the fancy stuff and just fight for the ball.

Colorado clinched its win thanks to Erpen. Gomez played a ball to winger Terry Cooke, who was deep into the attacking third yet still had time to fake a cross. When nobody stepped to him, he clipped a ball that dropped between two markers for Erpen to head past Wells.

Much grit and spirit is missing because of Josh Gros's retirement and the persistent, perhaps permanent, ankle problems suffered by Ben Olsen.

Gallardo sat out the Chicago game and hopefully took notes on how Blanco has adapted his audacious skill and fiery temperment to the rigors of MLS.

Soehn and technical director Dave Kasper can search for players in South America and Africa and anywhere else, but casting their net so far and wide is what got them into this mess.

Time isn't running out but neither is it on their side. The rest of May presents: a trip next weekend to Chivas USA, smarting over a 5-2 thumping by the Galaxy; home and away games four days apart with resurgent Toronto FC; and a trek to New England. Driving out the demons won't be easy.