The Nationals have signed veteran left-hander J.C. Romero to a minor-league contract and assigned him to Class AAA Syracuse, according to a club source.
Romero, 35, was designated for assignment by the Phillies on June 16 after losing his late-inning role to fellow relievers Antonio Bastardo and Mike Stutes. He posted a 3.86 ERA in 24 games, though he put 29 men on base in only 16 1/3 innings.
A key member of Philadelphia's championship bullpen the past four seasons, Romero owns a career 4.07 ERA in parts of 13 seasons with the Twins, Angels, Red Sox and Phillies.
Romero will report to Syracuse but could be an option for Nationals general manager Mike Rizzo to promote later this summer. The club has been without a consistently effective left-handed reliever this season, with Sean Burnett struggling and Doug Slaten on the disabled list.