The Nationals optioned Abbott to Triple-A Rochester on Sunday.
Abbott was sent back to Triple-A to make room on the 26-man active roster for right-hander Mason Thompson (knee), who was reinstated from the 15-day injured list in a corresponding move. During his latest stint with the Nationals, Abbott made 14 appearances out of the bullpen and compiled an 8.37 ERA and 1.94 WHIP over 23.2 innings.