Einar Díaz, a catcher from Chiriquí, Panama, made his entry into Major League Baseball when he was signed by the Cleveland Indians as an amateur free agent in 1990. His journey to the major leagues was marked by years of development in the minor leagues, where he honed his skills behind the plate. Díaz's major league debut came on September 9, 1996, with the Cleveland Indians, a team that would become his home for several seasons.

During his tenure with the Indians, Díaz primarily served as a backup catcher, providing depth to the team's roster. His role expanded in the 1999 season when he became more involved in the team's regular rotation. Known for his defensive abilities, Díaz was valued for his strong arm and ability to manage pitchers effectively. His offensive contributions were modest, but he was recognized for his ability to make contact and put the ball in play.

The 2001 season was a turning point for Díaz, as he became the Indians' primary catcher following the departure of Sandy Alomar Jr. He played in 132 games that year, achieving a .277 batting average with 3 home runs and 56 RBIs. His performance behind the plate was instrumental in helping the Indians secure a playoff berth. Díaz's ability to handle a pitching staff and his defensive prowess were assets to the team during this period.

In 2002, Díaz continued to be a regular presence for the Indians, appearing in 118 games. However, his offensive numbers saw a decline, with a batting average of .206. Despite the dip in his batting performance, his defensive skills remained reliable, and he continued to be a trusted figure for the pitching staff.

Following the 2002 season, Díaz was traded to the Texas Rangers in a deal that included Travis Hafner. With the Rangers, Díaz's role shifted once again, as he shared catching duties with other players. His time in Texas was marked by a continuation of his defensive strengths, though his offensive production remained limited.

Díaz's career saw further transitions as he moved to the Montreal Expos in 2004, where he played a backup role. His tenure with the Expos was brief, and he soon found himself with the St. Louis Cardinals in 2005. With the Cardinals, Díaz served as a backup catcher, contributing to the team's depth during their run to the National League Championship Series.

In 2006, Díaz signed with the Los Angeles Dodgers, but his time with the team was short-lived. He was released before the start of the season and subsequently signed with the Pittsburgh Pirates. However, he did not appear in any major league games for the Pirates, marking the end of his playing career in Major League Baseball.

Throughout his career, Díaz was known for his defensive capabilities and his ability to work well with pitchers. While his offensive numbers were not standout, his contributions behind the plate were valued by the teams he played for. After retiring as a player, Díaz transitioned into coaching, sharing his knowledge and experience with younger players.