Nationals activate LHP Detwiler to start Thursday
To make room for Detwiler on the roster the Nationals optioned right-hander reliever Erik Davis to Triple-A Syracuse.
Detwiler was 2-4 with a 2.76 ERA in eight starts this season with Washington before missing the last 24 games with a right back muscle strain. In his last start, on May 15, he allowed two runs in three innings before leaving the game with lower back spasms.
Detwiler allowed one run on seven hits with four strikeouts in 3 2-3 innings during his rehab start Saturday with Single-A Potomac.
Davis, 26, posted a 6.23 ERA with seven strikeouts in 4.1 innings during five appearances this season with Washington.