Turner, 21, was the Padres' first-round pick (13th overall) in the 2014 Draft. Under old baseball rules -- which have since been changed because of his trade -- he couldn't officially be traded until a year after he was drafted.
Until Sunday, Turner was unofficially part of the three-way trade with Tampa Bay and the Washington Nationals that brought Myers, catcher Ryan Hanigan, right-handed pitcher Gerardo Reyes and left-handed pitcher Jose Castillo to the Padres. Hanigan was then traded to the Boston Red Sox for third baseman Will Middlebrooks.
The Padres sent catcher Rene Rivera, infielder Jake Bauers and right-handed pitcher Burch Smith to Tampa Bay and right-handed pitcher Joe Ross and Turner to the Nationals.