The Washington Nationals activated relief pitcher Tony Sipp from the 10-day injured list and claimed reliever Javy Guerra on outright waivers from the Toronto Blue Jays.
The Nationals also designated left-handed pitcher Dan Jennings for assignment.
Sipp is 1-1 with a 6.00 ERA in 17 games this season, his first with Washington. The 35-year-old left-hander had pitched 5 1/3 scoreless innings in seven appearances before going on the injured list May 7 with a strained left oblique.
The right-hander Guerra, 33, posted a 3.86 ERA with 15 strikeouts in 14 innings across 11 appearances for Toronto in 2019. The nine-year veteran has a career record of 8-11 with a 3.44 ERA in 212 appearances, spanning 227 1/3 innings.
Jennings, 32, went 1-2 with a 13.50 ERA in eight appearances (4 2/3 innings) out of Washington bullpen this season.