The three-day "concentración" begins Monday at the Mexican federation's training center in Mexico City.
On Sunday, Castillo started for Santos in its 1-1 tie with UNAM. Ochoa, who played for Sierra Vista High School and was an NAIA All-American at Azusa Pacific University, scored for Monterrey in its 2-0 win over Indios Juarez.
Jose Francisco Torres, who turned down an invitation to play for the U.S. Olympic team, was the only other American to play on the second day of play in Mexico's Torneo Apertura, coming on as a second-half substitute in Pachuca's 3-2 home loss to San Luis.
In other action, Dan Califf played all 90 minutes for FC Midtjylland o its 2-1 win over AC Horsens in Denmark's Super League. Jeremiah White started for AGF in its 3-1 loss at OB.
In English preseason action, Brad Friedel made a sensational debut for Aston Villa, stopping a penalty kick in its 1-1 tie with Reading.
The 37-year-old Friedel knocked away Stephen Hunt's penalty kick -- awarded after American Bobby Convey was taken down in the box -- just 10 minutes into his first start for his new club.
"He didn't need a penalty save to prove he's a class goalkeeper, his overall performance was really very commanding and so assured," said Villa manager Martin O'Neill. "I think that given an injury free run he will do well for us."