Parker played in Major League Baseball (MLB) for the Seattle Mariners, New York Yankees and Detroit Tigers (1990) in parts of four seasons spanning 1987–1992.

[1] He made his MLB debut on September 14, 1987 against the Cleveland Indians, allowing three earned runs on five hits and one walk, while striking out five on 2⅓ innings of work and did not have a decision.

During the offseason, he was sent along with Lee Guetterman and Wade Taylor to the New York Yankees in the same transaction that brought Henry Cotto to the Mariners.

In between, Parker played winter ball with the Leones del Caracas club of the Venezuelan League in the 1987–1988 season, as he went 1-0 with a 1.56 ERA in four starts.

[5] Clay is a Partner and Senior Investment Advisor with the wealth management firm Southport Capital in Chattanooga, TN[6]