Jonny Venters had been spotless in three appearances with the Nationals before his injury. (John McDonnell/The Washington Post)

Amid a flurry of activity Thursday, the Washington Nationals placed reliever Jonny Venters on the 10-day injured list with an undisclosed injury. The move was retroactive to Monday, meaning the earliest Venters will be eligible to return is July 18.

The 34-year-old left-hander joined the team June 25 and had since appeared in three games. In the first two, Venters turned in a clean slate over 2⅓ innings, but in his latest appearance, July 5, which was the second of a back-to-back, he allowed three runs, two earned, and three hits in an inning and took the loss against the Kansas City Royals.

No corresponding move to replace Venters was announced, but the Nationals also transferred three pitchers — Erick Fedde, Austin Voth and Kyle McGowin — from Class AAA Fresno to Class AA Harrisburg the same night. The move was seemingly made to have all three available on short notice for the second half, which starts Friday night in Philadelphia against the Phillies.

Reliever Justin Miller, who has been on the IL since May 18 with a rotator cuff strain, was sent on a rehab assignment, also to Harrisburg. There, Miller joined reliever Kyle Barraclough, who was optioned to Harrisburg on Wednesday after a stint on the IL with radial nerve damage.

One of the four active pitchers there could be Venters’s replacement.

It’s also worth noting that Manager Dave Martinez intimated heading into the all-star break that he expected the Nationals’ fifth starter to remain Voth. This move gives the team flexibility with its starters, as well as the bullpen.

After the series in Philadelphia, the Nationals will visit the Baltimore Orioles and the Atlanta Braves, making East Coast-based Harrisburg a much more convenient location should they need to recall a pitcher.

The Nationals wound up with Fresno as their Class AAA affiliate last offseason after several closer options didn’t work out. The Nationals’ previous Class AAA affiliate, the Syracuse Chiefs, was bought by the New York Mets organization.

Since the Nationals last saw Fedde pitch June 20, he has struggled in the notoriously offense-heavy Pacific Coast League. With the Grizzlies, Fedde has started twice, thrown 10 innings, allowed 19 hits and 14 runs and walked four against 10 strikeouts.

McGowin has shown improvement since the Nationals sent him down May 29. He has thrown 19 innings and yielded six runs, and his latest performance was a seven-inning shutout.

The Nationals don’t seem to be sure what exactly they will do with the fifth starter role and in the bullpen, but now, at least, they have all the candidates close.

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