Mendez, whose career spanned 20 seasons between 1907 and 1926, put up some monster years in the Cuban League, posting documented records of 15-6, 11-2, 10-0 and 7-0 while winning three pennants in six years with Almendares.
His performance in 1908 made him a legend when he pitched 25 consecutive scoreless innings against the Cincinnati Reds including a one-hitter, then a few days later throwing a couple of shutouts including a no-hitter against a Minor League All-Star team, giving him 43 consecutive shutouts innings pitched.
His career record in the Cuban League was an incredible 76-28, good for a sparkling .731 winning percentage.
In the very first Negro League World Series in 1924, pitching for the Kansas City Monarchs, he appeared in four games against the Hilldale Club, going 2-0 with a shutout in the final game.
An early member of the Cuban Baseball Hall of Fame, elected in 1939 1939, he would add to that honor by being inducted to the U.S. Baseball Hall of Fame in 2006.