The release of Beck, 27, came just two days after the Dolphins picked quarterback Pat White of West Virginia in the second round of the 2009 draft. White is expected to operate the "Wildcat" offense for the Dolphins, but also to challenge one-year veteran Chad Henne for the No. 2 job behind starter Chad Pennington.
"We want to thank John for his work ethic and his professionalism," Miami general manager Jeff Ireland said. "We wish him well in the future."
A second-round choice in 2007, Beck was thought to have a bright future with the Dolphins. But that was before they selected Henne in the 2008 draft. The choice of White in the second round on Saturday, all but sealed Beck's fate with the club.
Beck, a former Brigham Young star, was a second-round pick in 2007.
He appeared in five games with four starts as a rookie, completing 60 of 107 passes for 559 yards, with one touchdown pass, three interceptions, and a quarterback rating of 62.0. Beck did not appear in a single game, however, in 2008.
Given his potential and his young age, Beck is likely to draw interest now from several teams as a free agent.
Senior writer Len Pasquarelli covers the NFL for ESPN.com.