Duffey informed the Rangers on Sunday that he intends to opt out of his minor-league contract, Robert Murray of FanSided.com reports.
Duffey's stay with the Rangers organization lasted just over two weeks, with the right-hander making four relief appearances at Triple-A Round Rock while striking out five over five innings and allowing one unearned run on five hits and four walks. His decision to pursue free agency likely was a result of Duffey not getting the impression that he was in line for a call-up to the Rangers when the 26-man active roster expands to 28 on Thursday.