Nationals Place Kelvin Herrera On DL, Recall Koda Glover

3:50pm: An MRI revealed no structural damage in Herrera’s shoulder, Chelsea Janes of the Washington Post tweets.

1:45pm: The Nationals announced today that they have placed reliever Kelvin Herrera on the 10-day disabled list with a right rotator cuff impingement. He’ll be replaced by Koda Glover, who’ll make his MLB season debut.

Needless to say, this represents a disappointing development for a Nats club that already failed to capitalize on a chance to make up some ground in the division yesterday. The club lost a game that Max Scherzer started, with Herrera surrendering the go-ahead runs before leaving the mound with a trainer.

The loss of Herrera is particularly worrying with first-choice closer Sean Doolittle already on the shelf. That said, the 28-year-old has not dominated to the extent expected when the Nationals picked him up earlier in the season from the Royals.

Over 17 innings in D.C., Herrera has allowed nine earned runs on 23 hits with 7.9 K/9 and 4.2 BB/9. His 1.824 WHIP sits quite a bit higher than the elite 0.818 mark he carried earlier in the year with the Kansas City organization.

This represents the latest change in the composition of the relief corps. Beyond the temporary absences of Herrera and Doolittle, the Nats recently parted ways with Brandon Kintzler and Shawn Kelley while adding Greg Holland and now Glover.

Though Glover has been seen as a potentially significant late-inning contributor by the organization, he has faced some roadblocks. He was carrying a 5.12 ERA last year, despite much more promising underlying numbers, when he went down with back and arm issues.

Glover’s next MLB appearance will be his first since June 10th of last year. He has shown some promising signs of late, however, throwing eight innings of 2.25 ERA ball with a 10:2 K/BB ratio thus far at Triple-A Syracuse.