The Colorado Rapids refused to release Pablo Mastroeni until three days before the United States' World Cup qualifying opener against Grenada, causing American Coach Bruce Arena to drop the defender and three Kansas City players yesterday.

Colorado will play Kansas City next Wednesday and under FIFA rules clubs aren't required to release players to the U.S. team until Thursday.

The Americans open their home-and-home series against Grenada on June 13 at Columbus, Ohio.

Arena also dropped Kansas City goalkeeper Tony Meola, forward Josh Wolff and midfielder Kerry Zavagnin.

"In the interest of fairness to both clubs, as well as the desire to have continuity in our training camp, I decided to remove all four players from the roster," Arena said.

Jonny Walker of the MetroStars will replace Meola as the backup goalkeeper to Kasey Keller. Arena must trim one more player before the game to get down to the roster limit of 18.

The revised roster:

Goalkeepers: Kasey Keller (Tottenham Hotspur, England), Jonny Walker (MetroStars).

Defenders: Carlos Bocanegra (Fulham, England), Steve Cherundolo (Hannover 96, Germany), Bobby Convey (D.C. United), Cory Gibbs (Dallas), Frankie Hejduk (Columbus), Eddie Pope (MetroStars), Tony Sanneh (Nuremberg, Germany), Greg Vanney (Bastia, France).

Midfielders: Chris Armas (Chicago), DaMarcus Beasley (Chicago), Landon Donovan (San Jose), Eddie Lewis (Preston North End, England), Claudio Reyna (Manchester City, England), Earnie Stewart (D.C. United).

Forwards: Conor Casey (FSV Mainz, Germany), Jovan Kirovski (Los Angeles), Brian McBride (Fulham, England).

-- Associated Press