The Washington Nationals released right-handed reliever Trevor Rosenthal on Sunday after his struggles continued in his second stint in the major leagues this season.

Rosenthal had a 22.74 ERA in 6⅓ innings over 12 appearances this season. In his final game for Washington on Saturday, he allowed three earned runs and three walks without recording an out as the Nationals blew a four-run lead in a 13-9 loss to the Braves.

'"He's got great stuff,'' Nationals manager Dave Martinez said. "He just couldn't find the strike zone.''

Rosenthal retired the only batter he faced Friday night before bottoming out Saturday night.

"I was very hopeful he had turned a corner,'' Martinez said. "We're up four runs (on Saturday), we're down a couple guys, and to me, that was his spot. It just didn't work out.''

Washington also optioned right-hander Joe Ross to Triple-A Fresno. Ross was the losing pitcher Saturday after giving up four earned runs and five hits in the eighth inning. He had been considered for a start Sunday before being used in Saturday's game.

Rosenthal, 29, had rejoined the Nationals in June after starting the season with a 36.00 ERA in seven games -- not recording an out over his first four appearances -- and agreeing to go to extended spring training.

Things didn't go much better upon his return, as he had a 10.80 ERA over five appearances this month.

The Nationals have a major league worst 6.32 ERA from their bullpen this season.

An All-Star in 2015 with the St. Louis Cardinals, Rosenthal underwent Tommy John surgery in 2017 and missed all of the 2018 season.

The Nationals recalled right-handers Austin Voth and Kyle McGowin to fill the open roster spot. Voth, 26, was 1-1 with a 6.57 ERA in four games (two starts) for the Nationals last year, while McGowin has a 9.90 ERA in three games (one start) for Washington this year.

The Associated Press contributed to this report.