White, taken in the second round of the 2009 NFL Draft after a dynamic college career at West Virginia, failed to materialize with the Dolphins. He fell to fourth on the depth chart and rarely played in the preseason.
An outfielder who bypassed joining major-league teams after being drafted to pursue a football career, White is expected to begin in an instructional league this fall, a source close to the quarterback said.
The Dolphins released White on Sept. 4, the final day of cutdowns.
White struggled with his throwing accuracy during a disappointing rookie season in 2009, when he failed to complete any of his five passes in limited duty. The Dolphins kept three quarterbacks -- Chad Henne, Chad Pennington and Tyler Thigpen -- this season.
Tantalized by the athletic talents showcased in college, Miami drafted White with the idea of using him as a weapon in the Wildcat offense. But White struggled to adapt to the NFL in his rookie season, and Dolphins coach Tony Sparano used the quarterback for just three snaps in three preseason games last month.
White has been drafted by major-league teams four times, most recently by the New York Yankees in 2009.
The Associated Press contributed to this report.