Detwiler, a 2007 1st round pick, has pitched parts of seven seasons with the Nats, and was forced out of the rotation entering the 2014 season. The move to the bullpen came after an injury plagued 2013 season, in which he only made 13 starts. In 2012, Detwiler had the most productive year of his career, posting a 3.40 ERA over 33 games and 27 starts. The Nats' decision to move him to the bullpen in 2014 came after the addition of Doug Fister, as well as the emergence of RHP Tanner Roark. The decision turned out to be a smart move by the Nats, as Fister would post a 2.41 ERA over 25 starts, while Roark would post a 2.85 ERA over 31 starts. In Detwiler's first full season in the 'pen, he would post a 4.00 ERA over 63 innings pitched in 47 appearances.
Detwiler will have a chance to reestablish himself as a starting pitcher with the Rangers, as Matt Harrison and Martin Perez are expected to start the year on the disabled list. With Yu Darvish, Derek Holland, and Colby Lewis established as the top three starters, Detwiler and Nick Tepesch will fill out the back end of the rotation. For the 2014 season, Tepesch posted a 4.36 ERA over 23 starts.
In exchange for Detwiler, the Nats will receive prospects Abel De Los Santos and Chris Bostick. De Los Santos, a 22 year-old native of the Dominican Republic, spent the 2014 season with low-A Hickory and advanced-A Myrtle Beach. In 41 relief appearances, De Los Santos a 1.92 ERA for the season. Bostick, a second baseman out of Rochester, NY, spent his only season with the Rangers organization with the Myrtle Beach Pelicans. Bostick would post a .251/.322/.412 slash line in 130 games, along with 24 SB. Bostick, originally drafted by Oakland, was traded with Michael Choice to the Texas Rangers, in exchange for Craig Gentry and Josh Lindblom, in December of 2013.