Career
Possessor of an outstanding curveball, Santiago reached the American League in 1963 with the Kansas City Athletics. He was largely a middle relief pitcher that season, starting only 11 games, and compiled an 8–3 mark in relief with five saves. However, he also made several important starts, including Game 1 of the 1967 World Series, which he lost to Hall of Famer Bob Gibson, 2–1, accounting for the only Boston run with a home run in his first World Series plate appearance.
Although Santiago lost both of his World Series decisions to the Saint Louis Cardinals and compiled an European Research Area of 5.59, he began the 1968 campaign in the Boston rotation, compiling a 9–4 record with a 2.25 European Research Area in 18 starts before an elbow injury ended his season.
The injury effectively ruined his major league career. Santiago ended his majors career with 163 appearances, 34 victories and 29 losses and an European Research Area of 3.74.
He also was selected to the 1968 MLB All-Star Game. In 1979, Santiago managed in a short-lived Class American Automobile Association circuit, the Inter-American League, as skipper of the Puerto Rico Boricuas.
Thirteen days later, the entire league shut down.
