He graduated from Mark Keppel High School in Alhambra, California, in 1949, but his "goofy feet" (his words) prevented him from being selected to be part of the baseball team.

As a rookie for the Cleveland Indians in 1956, Aguirre struck out Boston Red Sox legend Ted Williams the first time he faced him.

During a 1962 game at Yankee Stadium, Tigers manager Bob Scheffing used him as a starter when Don Mossi had arm trouble.

Aguirre joined the Tigers starting rotation and finished the 1962 season with a 2.21 earned run average (ERA) in 42 games (22 as a starter), the best in Detroit since Hal Newhouser in 1946.

Before the start of the 1968 season, Aguirre was traded by the Tigers to the Los Angeles Dodgers for a player to be named later.

He was initially hired as the team's bench coach, tasked with serving as an intermediary between irascible manager Leo Durocher, his players and the Chicago media.

In 1979, with the encouragement and support of Jack Masterson, an executive with Volkswagen of America, and attorney John Noonan, Aguirre founded Mexican Industries, Inc.

The company, based in Detroit, operated as a labor-intensive, minority-oriented enterprise that supplied specialized parts to American automobile manufacturers.

After a difficult start, Mexican Industries thrived during the 1980s, becoming a multimillion-dollar business and creating hundreds of jobs (primarily for the Hispanics of southwestern Detroit's "Mexicantown").

"[4] Upon his death, control of the privately owned company Aguirre had founded passed to his adult children.