By Ridge Mahoney

Heading into last weekendÆs Western Conference final against Colorado, two Houston players were ensnared in what MLS quaintly calls ''yellow peril,'' i.e., players cautioned once in the playoffs and thereby facing suspension if they were cautioned again.

For MLS Cup 2006 on Sunday against New England, one of those players will likely replace the other.

Adrian Serioux, converted from a defensive midfielder to central defender during the season by Coach Dominic Kinnear, got through the Rapids game without a yellow, but Ricardo Clark went into the book with just 17 minutes played. His midfield foul seemed innocuous, but referee Brian Hall has just cautioned Clint Mathis for dissent and perhaps his blood was still boiling.

''I feel bad for the kid because heÆs been great for us this year,'' says Kinnear of Clark, who, like Serioux, came west from the MetroStars/Red Bulls.

Clark had set up an equalizer in the 11th minute by playing a ball forward that Dwayne DeRosario forwarded to Paul Dalglish, who slipped it under Joe Cannon. That goal matched a Colorado penalty kick resulting from Serioux batting down a corner kick while tussling with Jovan Kirovski.

''YouÆd think heÆd be affected because he got it early but you think about the work he put in even knowing he couldnÆt play in the final,'' says Kinnear of Clark. ''HeÆd be a good player for any team in this league.''

If he moves Serioux into midfield, aside from forming a Canadian central tandem with DeRosario, someone else must play in the middle with Eddie Robinson. If ther'Æs one spot that's been a bit unsettled for Houston, itÆs this slot, vacated last winter when Danny Califf left for Europe.

Serioux, acquired from the Red Bulls in exchange for yet another defensive midfielder, Danny ORourke, was one of the few player changes to an ex-Earthquakes team that ran away with the Western Conference last year, was stunned by the Galaxy in the playoffs, and then hauled off for Houston.

''He would try things that as a center back you wouldn't try, because if you get nicked there's nobody behind you,'' said Robinson of SeriouxÆs move to the back line. ''He's made the adjustment and he's been fantastic to play besides.''

Ryan Cochrane, who started 24 games in the regular season and has come on as a sub twice in the playoffs, is first choice to take over at central defense, but Kinnear could also slide Craig Waibel from right back into the middle. Then heÆd need to find a right back; an excellent choice would be Clark, but that option isnÆt available.

''It hurts us in a couple of ways: you have to adjust and youÆre taking a very good player off the field,'' says Kinnear. ''Ryan's been partnered with Adrian there, heÆs partnered Craig Waibel, heÆs partnered Eddie, so he's ready.

''But we always have to think about what is the best approach for us. That seems logical right now but we have to think it through so we can find the best way to keep our midfield together and our back four together.''

Against a Revs midfield that features the power and speed of Shalrie Joseph, the experience and leadership of Joe Franchino, the mobility and guile of Andy Dorman as well as, possibly, Steve Ralston and/or Clint Dempsey and/or perhaps Pat Noonan, how the Dynamo copes without Clark û as well as a numerical disadvantage — is a crucial factor.

Unless New England resorts to its tactics in the conference final against D.C. and starts with four in the back, its five-man midfield would figure to outnumber HoustonÆs quartet. Yet even without Clark, the Dynamo midfield — with Brad Davis on the left, Brian Mullan on the right, and talisman DeRosario prompting the attack — is a varied and potent element.

''Brad [Davis] likes to tuck inside a little bit but if he's wide he's still good,'' says Kinnear. ''You have Brian Mullan, who's almost like an old-fashioned winger. Dwayne likes to use his range, so itÆs a good balance.''