The  Dodgers and  Padres will play Major League Baseball’s first regular-season games in South Korea, opening next season in Seoul on March 20-21. The Houston Astros and Colorado Rockies will play in Mexico City on April 27-28, MLB said Wednesday. The Padres and San Francisco Giants played the first regular-season games there this past April. Overall, MLB will have three sets of international games next year. A two-game series in London on June 8-9 between the New York Mets and Philadelphia Phillies was announced last month.  MLB also said the Boston Red Sox and Tampa Bay Rays will play spring training games at Santo Domingo, Dominican Republic, on March 9-10.