PHOENIX -- Stephen Strasburg was one of the most dominant pitchers in MLB in July. His first outing of August did not go nearly as well.

The reigning National League Pitcher of the Month gave up a career-high-tying nine runs in the Nationals’ 18-7 loss to the D-backs on Saturday night at Chase Field. Strasburg has allowed six or more runs only three times this season, two of which have come against Arizona.

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Three of Strasburg’s nine hits allowed were home runs -- a two-run homer by Eduardo Escobar in the first, a solo shot by Nick Ahmed in the second and a two-run homer by Jake Lamb in the fifth. It was only the third time this season that Strasburg has given up three home runs. He yielded a season-high four in a loss to the D-backs on June 15.

“They were looking for the ball up in the zone, and when they got it, they hit it hard,” Nationals manager Dave Martinez said. “The one pitch to Ahmed was right down the middle. He just wasn’t locating.”

The only other time Strasburg allowed nine runs in a start was Aug. 17, 2016, against the Rockies.

In Strasburg’s two starts against Arizona this season, he's pitched 9 2/3 innings and allowed 15 earned runs on 18 hits, with a 2.17 WHIP and a .383 average against. On Saturday, the D-backs put eight balls into play with an exit velocity of more than 100 mph against the right-hander, per Statcast, including five hits and all three of the homers Strasburg allowed.

After watching video, Strasburg found something that he believes was causing the D-backs to jump on his pitches. And while he won’t face them again this season, it could be beneficial knowledge to help him get back on track his next time out.

“They’ve tattooed me twice this year, so that seems to be obvious,” Strasburg said. “It’s my job to mix up pitches, execute pitches, and it’s their job to put the barrel on the ball, and they did that tonight. I can’t really be too frustrated about it, but I do know that I have to go out there and be better next time. It’s the little things that can sometimes become big things if you don’t manage them well.”

The Nationals took a 2-0 lead before Strasburg took the mound, as Adam Eaton hit an RBI triple and Anthony Rendon had a sacrifice fly in the first. But the D-backs scored runs in each of the first three innings to erase their early deficit.

After Strasburg exited with two outs in the fifth, left-hander Matt Grace immediately gave up a two-run homer to Alex Avila, which capped a five-run inning for the D-backs that put them ahead, 10-4.

To save their bullpen arms late, the Nats moved Gerardo Parra from first base to the mound at the start of the eighth inning. He issued four walks and gave up one hit, allowing five runs without recording an out. Second baseman Brian Dozier then took over, giving up a two-run homer to Escobar over one inning.

It was the first time in Nationals history that they used two position players on the mound in the same game. It was also the first career pitching appearances for both Parra and Dozier.

“The bullpen has pitched a lot,” Martinez said. “I just didn’t want to run anybody else out there and come back [Sunday] fresh.”

Washington is now tied with Philadelphia for the second National League Wild Card spot. However, if the Nats are going to reach the postseason, they’ll likely need Strasburg to pitch more like he did in July, when he went 5-0 with a 1.14 ERA over five starts.

The key now is for Strasburg -- and the rest of the Nationals -- to turn the page after a tough night for all.

“We got our butts kicked today, but they were in good spirits, they were ready to go,” Martinez said. “Let’s come back [Sunday] and play to win.”