By THOMAS FLOYD

For the one and only time in 2012, the Texas derby will be contested Saturday.

Perhaps the most notable casualty of the league's move to an unbalanced schedule this season, the rivalry match will see FC Dallas travel to BBVA Compass Stadium to take on the Houston Dynamo. With a win, the home side will retain El Capitan — a replica Civil War cannon claimed by the derby winner.

Elsewhere around the league this weekend, the Philadelphia Union and Toronto FC will both debut interim coaches when those clubs face D.C. United and Sporting Kansas City, respectively. And the Montreal Impact will debut their renovated permanent home, hosting the Seattle Sounders at Saputo Stadium.

Here is a rundown of the full Week 15 slate:

PHILADELPHIA UNION vs. D.C. UNITED (Saturday, 7 p.m., Galavision)

John Hackworth's first match stepping in for the departed Peter Nowak will be a tough test against Eastern Conference-leading D.C. United, who are on a three-game winning streak in league play but will want to avenge a 2-1 loss to the Union earlier this month in the U.S. Open Cup.

United coach Ben Olsen will have a lot of tough choices to make, with every player except for rookie Lance Rozeboom (torn ACL) healthy and available for selection if needed.

VANCOUVER WHITECAPS vs. COLORADO RAPIDS (Saturday, 7 p.m., Direct Kick)

With both of these teams in the middle of the Western Conference pack, this matchup could add some clarity to the balance of power on that side of the table.

For Colorado, the emphasis will be on stopping Vancouver rookie Darren Mattocks, who is coming off a two-goal performance in Vancouver's 3-1 win over Houston last weekend, while the Whitecaps' stingy defense will be tasked with keeping Conor Casey and Co. in check.

MONTREAL IMPACT vs. SEATTLE SOUNDERS (Saturday, 7:30 p.m., TSN2)

After playing their first five home games at Olympic Stadium (going 2-1-2), the Impact will debut an upgraded Saputo Stadium with capacity increased to more than 20,000.

Winless in four, Seattle was dealt a tough blow when midfielder-forward David Estrada broke his foot Tuesday. With the UCLA product sidelined 8-to-12 weeks, even more of the scoring burden will fall on forwards Fredy Montero and Eddie Johnson.

NEW ENGLAND REVOLUTION vs. COLUMBUS CREW (Saturday, 7:30 p.m., Direct Kick)

This series between longtime Eastern Conference foes has been heavily tilted in the Crew's favor lately, as Columbus has gone 7-2-1 in its last 10 against New England.

For the Revolution, this match marks a key stretch in which they will play four out of five at home. New England is 4-1-1 at home this season, but a dismal 1-6-0 away from Gillette Stadium.

HOUSTON DYNAMO vs. FC DALLAS (Saturday, 7:30 p.m., ESPN2)

It would require a small miracle for Dallas to grab a win on the road and take El Capitan from Houston. The visitors, after all, are 0-6-1 on the road this season and have lost seven of their last eight in all competitions.

The Dynamo will get a slew of players back from international duty in this contest, with Geoff Cameron (U.S.), Andre Hainault (Canada), Jermaine Taylor (Jamaica) and Je-Vaughn Watson (Jamaica) all returning to action.

SPORTING KANSAS CITY vs. TORONTO FC (Saturday, 8:30 p.m., Direct Kick)

Kansas City had just gotten back to its winning ways with a 2-1 triumph over the San Jose Earthquakes when MLS went into its near-hiatus. Peter Vermes' side will look to make it two in a row with a home win against Paul Mariner's 1-9-0 Toronto FC side.

The visitors' interim boss will look to build off the small amount of momentum Aron Winter built at the end of his tenure, when Toronto claimed the Canadian championship before grabbing its first MLS win of 2012 against Philadelphia.

CHIVAS USA vs. REAL SALT LAKE (Saturday, 10:30 p.m., Direct Kick)

Salt Lake will be looking to avenge one of the early shock results of 2012, when Chivas traveled to Rio Tinto Stadium and stole a 1-0 win thanks to a scrappy goal from rookie Casey Townsend.

Real Salt Lake will welcome back goalkeeper Nick Rimando and captain Kyle Beckerman, both of whom spent the past several weeks with the U.S. national team. While Salt Lake hasn't lost in six, Chivas have quietly gone unbeaten in four.

CHICAGO FIRE vs. NEW YORK RED BULLS (Sunday, 5 p.m., NBC Sports)

A point back of D.C. United for first place in the Eastern Conference (with two games in hand), the Red Bulls will look to grab a win on the road against Chicago and move back atop the table, though they'll have to do so without injured Designated Players Thierry Henry (calf) and Rafa Marquez (thigh).

That means a Fire defense that will be without Arne Friedrich (hamstring) will have to concentrate on New York forward Kenny Cooper, who is tied for the league lead with 11 goals.

LOS ANGELES GALAXY vs. PORTLAND TIMBERS (Sunday, 7 p.m., Direct Kick)

Having lost three in a row, the last-place Galaxy will look to claim a crucial three points at home against a Portland team that is unbeaten in four. Although Robbie Keane is still with Ireland at Euro 2012, Los Angeles will get Landon Donovan back from U.S. national team duty.

For the Timbers, this match will mark the debut of striker Danny Mwanga, who was recently acquired from Philadelphia for forward Jorge Perlaza.