Of course, the game is not easy, and nights like Thursday will happen. Clippard allowed three runs in 2/3 of an innings, turning a one-run game into a 5-1 deficit. He surrendered three hits, including an RBI double and a two-run home run. It stood in stark contrast to the rest of his season.

“It was a combination of bad pitch selection and bad execution on my part,” Clippard said. “Usually, you’re not going to succeed when that happens. Tonight was a good indicator of that. I always feel like I’ve been pretty good at knowing what pitches to throw in certain situations. The swings the hitters were taking dictated otherwise. It’s up to me to see that, and I didn’t. It was a bad outing.”

The entire outing could have passed like most Clippard’s appearances, with him walking off the mound have kept the score the same as when he entered. With two outs and a man on first, Clippard got ahead of Miguel Montero 0-2 and fired a 93-mph pitch on the corner. It may have been a strike; Manager Davey Johnson thought so. But home plate umpire Tim McClelland called it a ball.


Clippard threw one more ball, and then he fired a 2-2 changeup. He later regretted that – he realized, in hindsight, Montero would be sitting on a changeup. Montero roped it into the right field corner for a double, scoring Justin Upton from first.

Against the next batter, rookie slugger Paul Goldschmidt, Clippard worked the count to 3-2. He threw another changeup, another mistake. Goldschmidt crushed the ball, and on one bounce it landed over the seats in left field, on the concourse. Clippard’s ERA had shot from 1.54 to 1.91.

That was it for Clippard, and on came Ryan Mattheus. He hit one batter and walked another, and then the Nationals noticed something wrong. Trainer Lee Kuntz, pitching coach Steve McCatty and Manager Davey Johnson visited the mound.

Mattheus left with what the Nationals called “tightness” in his right shoulder. Mattheus had left with the same ailment Aug. 18, when experienced tightness after lifting weights earlier in the day.

Mattheus said he felt “nothing out of the ordinary” and no pain in his shoulder. But he did notice the same drop in velocity his coach and manager saw, and he agreed that something was off as he pitched for the second straight day. He had less of a tight sensation Thursday than after he lifted weights last week.

Mattheus will rest for a few days before he pitches again. A doctor examined Mattheus and found no structural damage. It seems most likely that Mattheus just has a dead arm, and could be back to normal in a few days.

FROM THE POST

This tribute to Mike Flanagan by Boz is wonderful.

The Nationals’ offense fell flat in an 8-1 loss to the Diamondbacks, which dropped them to 5-5 on a homestand that started with great promise.

Steinberg surveys the response to Air Screech.

NATS MINOR LEAGUES

Pawtucket 12, Syracuse 4: Brad Meyers allowed two runs in six innings on hits and one walk, striking out five. Stephen Lombardozzi went 2 for 4 with a walk. Roger Bernadina went 1 for 4 with a home run.

Harrisburg 6, New Hampshire 4: Chris Rahl went 2 for 4 with a triple and a walk. Tyler Moore went 2 for 5 with a double. Erik Arnesen allowed two runs in 6 1/3 innings on seven hits and a walk, striking out seven.

Wilmington 11, Potomac 5: Zachary Walters went 2 for 3 with two walks. Francisco Soriano went 3 for 4 with a double. Eury Perez went 2 for 4. Catcher Brian Peacock pitched an inning, allowing no runs on two hits and a walk.

Hickory 5, Hagerstown 3: David Freitas went 2 for 4 with a double. Chris Curran went 2 for 5 with a double.

Auburn 4, Mahoning Valley 1: Hendry Jimenez went 1 for 3 with a home run. Justin Miller went 1 for 4 with a home run. Matt Skole went 2 for 4 with a double. Nathan Karns allowed one run in six innings on three hits and no walks, striking out six.