He played part of the 1972 season in Major League Baseball for the St. Louis Cardinals, primarily as a first baseman.

Originally signed by the Philadelphia Phillies on June 13, 1964, Allen began his professional career with the Miami Marlins of the Florida State League.

Allen's best day as a major leaguer was on August 17, 1972 at San Diego Stadium, due in part to teammate Joe Torre.

The next inning, he got his only major league hit, a home run against San Diego Padres right-hander Mike Corkins.

He graduated 46 years and 195 days after scoring his last point for the Penguins, fulfilling a promise made to his mother to earn his college degree.