The callup of Castillo, who plays for Tigres in Mexico and the Houston Dynamo's Stuart Holden and Ricardo Clark follows weekend play in Mexico and MLS.
Castillo played against Jose Francisco Torres, who was initially called into the U.S. team but then excused for personal reasons, in the final day of the Mexican First Division's regular season. The 1-1 tie eliminated Torres' Pachuca from the knockout phase. Castillo's Tigres had already been eliminated.
Castillo, who began his Mexico career at Santos and moved to Club America in January. He was loaned to Tigres this summer. He played for Mexico's national team in friendly games only.
Clint Dempsey (Fulham) and Steve Cherundolo (Hannover), who played in Saturday's 1-0 loss at Slovakia will return to their European clubs, while Chad Marshall, who has a sore knee, returned home.
GOALKEEPERS:Brad Guzan (Aston Villa), Marcus Hahnemann (Wolves), Troy Perkins (Valerenga)
DEFENDERS:Carlos Bocanegra (Rennes), Jonathan Bornstein (Chivas USA), Edgar Castillo (Tigres), Jimmy Conrad (Kansas City Wizards), Clarence Goodson (IK Start), Frankie Hejduk (Columbus Crew), Heath Pearce (FC Dallas), Jonathan Spector (West Ham)
MIDFIELDERS: Michael Bradley (Borussia Moenchengladbach), Ricardo Clark (Houston Dynamo), Benny Feilhaber (AGF Aarhus), Stuart Holden (Houston Dynamo), Sacha Kljestan (Chivas USA), Dax McCarty (FC Dallas), Robbie Rogers (Columbus Crew), Jose Francisco Torres (Pachuca)
FORWARDS: Jozy Altidore (Hull City), Conor Casey (Colorado Rapids), Jeff Cunningham (FC Dallas), Eddie Johnson (Fulham)