"I'm just embarrassed I let the team down," he said. "It stinks. I'm just trying to go out there and help this team win some games. I didn't do that tonight. I've just got to turn the page and get back on it tomorrow."
The problems weren't physical, Strasburg said. Asked how his back felt, he said: "It's good enough."
Asked if any of the mechanical things he had worked on carried into the game, Strasburg said: "What do you think? No, it didn't. I left a lot of pitches up. Didn't hit a spot. They're a good-hitting team, so I've got to do better."
Strasburg's pitching told the story. He was up in the strike zone with his fastball and couldn't spot his breaking pitches, Nationals manager Matt Williams said. Everything looked hittable as the D-backs pounded out eight hits, including homers by Ender Inciarte and Mark Trumbo, who finished with two blasts in the game.
Williams gave Strasburg a pass into the fourth inning, but when Trumbo jolted a three-run homer into the far reaches of the left-field seats with one out, the manager had seen enough.
"The fact that he got through it and felt good physically is good," Williams said. "His fastball was good, but he didn't locate it. And he got beat on his offspeed pitches. But physically he's good, and that's a positive sign for us."
Strasburg's next time out would come against the Padres five days from now on Sunday at Petco Park. Strasburg grew up in nearby West Hills and played his college ball for the late Tony Gwynn at San Diego State before the Nationals made him the No. 1 pick in of the 2009 First-Year Player Draft.
He's only pitched once before in his hometown since those college days, allowing just two runs on three hits in eight innings to earn the win on May 16, 2013. Strasburg knows right now he has some work ahead of him before he pitches his next game.
He's 2-4 and his ERA ballooned to 6.06 -- almost three runs higher than his career mark -- after Tuesday night's outing. This is the most sustained period of angst in his playing career.
"I've just got to keep my head down, keep battling, keep fighting," he said. "I'm just not making good pitches."
Can he pinpoint the problem?
"I'm just trying to figure it out," he said. "It wouldn't happen if I knew what it was."