After seven games in 1996, Allen began his first full professional season with the Fort Myers Miracle, where he had a .305 batting average over 105 games. He was then promoted to the New Britain Rock Cats, where he spent the rest of 1997 and the entire 1998 season. In 1998, he had a .262 batting average, 82 runs batted in (RBI), and 21 stolen bases.[4] After spring training, he made the opening day roster for the 1999 Minnesota Twins season, and spent the year as the team's starting left fielder. In 137 games, Allen had a .277 batting average, 10 home runs, and 14 stolen bases. He spent most of 2000 with the Salt Lake Buzz, and played 15 games in the majors. After 57 games with the Twins in 2001, he tore his ACL in August which ended his season; the Twins released him during the offseason.[2][5]
For the rest of his career, Allen remained mostly in the minor leagues. In 2002, he played five games for the Cleveland Indians. In 2003, he played 12 games for the Florida Marlins, and he played a combined 41 games over two seasons for the Texas Rangers; his last major league game was June 2, 2005.[2] At the start of the 2006 season, the Kansas City Royals assigned him to the Omaha Royals of the Pacific Coast League (PCL), where he had a .314 batting average in 105 games.[4]
