Born in San Pedro de Macorís, he batted left-handed, threw right-handed, and was listed as 6 feet 1 inch (1.85 m) tall and 185 pounds (84 kg).

In his first full professional season in 1958, he led the Northern League with a .340 batting average while playing for the Eau Claire Braves.

After hitting .325 for the Pacific Coast League Vancouver Mounties in 1961, he was acquired by the Athletics from the Milwaukee Braves in a multi-player trade.

Finley at first denied any interference but later admitted to reporters that he had indeed met with Jiménez after the manager and coaches had "unsuccessfully tried to do the same thing."

In 234 game appearances as an outfielder his fielding percentage was .966, which was below the major league average of .980 during the time he played.