[2] Espino began his baseball career in 1960 with the Tuneros de San Luis Potosí of the Mexican Central League.

His run total was the third highest in Mexican League history, being surpassed only by Bobby Ávila and Cool Papa Bell.

His impressive numbers drew the attention of the St. Louis Cardinals organization, who signed Espino late in the year and sent him to their AAA club, the Jacksonville Suns.

Espino returned to full-time duty in 1966 and hit a league-leading .369, beating out Minnie Miñoso by 21 points.

He finished second in the league with 31 homers and third with 91 walks despite missing two road series due to conflicts with his manager.

In 1972, Espino bounced back to a .356 average and clinched his fourth and final home run title (37).

In 1973 his average rose again, to .377, good to win his fifth and final Mexican League batting championship.

Overall, Espino won 13 batting crowns, six home run titles, and six Most Valuable Player awards.

[citation needed] In 1990 and 1991 Espino managed the Monterrey Industriales, posting a 110–138 record In 248 games for a .444 winning percentage.

During the course of his career, he rejected contract offers from the St. Louis Cardinals, New York Mets, San Diego Padres, and California Angels, which helped him earn the nickname, "The Rebel of Chihuahua."

His all-time minor league home run title and his intentional walks records — 53 in a season (1969) and 408 career (over 200 more than #2 Barrera) — have not been approached.

In 2020, Espino was selected as the first baseman on the Mexican League Historic Ideal Team by a committee of baseball journalists and historians.