Mendoza first caught the eye of the Pittsburgh Pirates while playing for the Mexico City Diablos Rojos of the Mexican League in 1970.

His ability for picking grounders prompted the Pirates to purchase Mendoza's contract from Mexico City.

He started game three of the 1974 National League Championship Series against the Los Angeles Dodgers, and went one for three with a walk and an RBI infield single.

[3] On June 28, 1977, Mendoza pitched two innings of mop up duty in the second game of a doubleheader against the St. Louis Cardinals.

[5] In his first season with the Mariners in 1979, he made a career-high 401 plate appearances in a career high 148 games and 132 starts at shortstop.

Mendoza was traded along with Willie Horton, Rick Honeycutt, Leon Roberts and Larry Cox from the Mariners to the Texas Rangers for Richie Zisk, Jerry Don Gleaton, Rick Auerbach, Ken Clay, Brian Allard and minor-league right-handed pitcher Steve Finch in an 11-player blockbuster deal on December 18, 1980.

After failing to make the team, he accepted a player-coach position with their triple A Pacific Coast League affiliate, the Hawaii Islanders.

His career batting average in Mexico was a substantially better .291; he earned the nickname Manos de Seda, or Silk Hands, for his fielding prowess.

The reference caught the attention of ESPN announcer Chris Berman, and the "Mendoza Line" became part of popular culture.