The Post Sports Live crew debates whether Bryce Harper's comments about manager Matt Williams' lineup are potentially damaging for a team that just got back to full strength on Monday night. (Post Sports Live/The Washington Post)

Standing at his locker in an otherwise barren clubhouse, Tanner Roark grinned, shrugged and said the one thing he could. He believed he had executed his pitches the way he wanted, at least when he threw what he wanted. He harbored no concern about two consecutive starts in which he allowed a total of 19 hits. He credited an opponent that battered him for the second time in a week, and he moved on. “I just got beat,” Roark said with a what-are-you-gonna-do smile on his face.

The Nationals’ five-game winning streak ended Friday with a lackluster 7-2 loss to the Chicago Cubs in front of a sellout Independence Day crowd at Nationals Park. The Cubs smacked nine hits and scored four runs in seven innings off Roark, who could not recover from an early barrage even with an efficient finish. Right-hander Jason Hammel muzzled the Nationals’ lineup, just like he did June 27 when he opposed Roark in the last game the Nationals had lost.

“It’s just one game,” center fielder Denard Span said. “You want to try to win every single game, but we’ll come back tomorrow ready to go. Chicago has been a hot team. They played us good last week and they just got done sweeping Boston, so we’re playing a hot team. We’ve got to find a way to try to cool them off tomorrow.”

Moved up to second in the lineup to face a right-handed starter, Bryce Harper went 0 for 4 with two strikeouts and stranded three runners, including two in scoring position, with two outs. As Manager Matt Williams warned may happen, Harper has started slow after returning from two months on the disabled list. In his first four games after missing 57, Harper is 3 for 15 with a walk and six strikeouts.

“He’s a little jumpy,” Williams said. “He’s jumping at it a little bit. That long a layoff, it’s a long time, so it takes some time to get back into the swing of it. He looks a little jumpy to me. Not quite seeing it as well as he can.”

Roark and Hammel both stood at 7-5 with a 2.98 ERA when they took the mound, the first time since 1974 that two pitchers with identical records, identical ERAs and at least 10 starts opposed each other. In the second inning, their ERAs separated.

Hammel ripped a line drive off Roark’s lower back, and the ball squirted into left field for an RBI single. Justin Ruggiano rocked a wind-aided homer to right field in the third, and the Cubs had taken a 3-1 lead.

On June 27 in Chicago, Roark had allowed 10 hits — three more than any other start this year — and four runs in six innings. Friday afternoon, Roark allowed nine hits and another four runs over seven innings. His ERA has risen from 2.79 to 3.12 in his past two starts.

Williams said Roark has been “just not as sharp,” missing with the location of his two-seam fastball. Roark believes he needs to be more willing to shake off his catcher’s sign and throw the kind of pitches he wants. Without conviction, he said, his stuff weakens.

“I got to execute pitches that I want and shake off whenever I want, and not just throw whatever the catcher is putting down,” Roark said. “I feel like that’s the biggest thing for me.”

Hammel shut down the Nationals for six two-run innings, bringing his career record against them to 8-0 with a 3.10 ERA. Seven days after he beat the Nationals, they took the same approach. “He still has the same pitches,” said Anthony Rendon, who went 1 for 4 with a double. “And you still got the same swings.”

Hammel used his menacing slider and low-90s, sinking fastball to hold the Nationals to five hits and squirm free from jams. “He was able to throw his breaking balls in the right location and get us out,” Span said. “I think that was the difference in the game. We had opportunities and we just weren’t able to capitalize.”

Jayson Werth provided half the Nationals’ offense with one swing. With two outs in the first inning, he blasted Hammel’s 3-1 fastball about 15 rows deep in the left field stands. He also smacked a double to right field in the eighth. In June, Werth managed one homer and five doubles. In just three July games, after he altered his stance to stand taller, Werth has three doubles and two homers.

The Nationals created their best chance to surge back in the fifth. With two on and no outs, Williams could have pulled Roark, sitting on only 65 pitches but having allowed nine hits in five innings, and tried to strike for a big inning with a pinch hitter. Williams opted to keep Roark in and let him bunt.

“It sets up perfectly for us, getting the bunt down, moving the guys to second and third with the top of the lineup coming up,” Williams said. “We’ve got a lot of game left there. It’s a little bit early. We wanted to certainly get one and hopefully two there.”

With the Cubs’ corner infielders creeping to within about 45 feet of home plate, Hammel misfired three straight pitches and ran the count to 3-0. But he came with three straight strikes, none of which Roark bunted fair, and Roark struck out.

Having given the Cubs one out, the Nationals stalled. Span hit a sharp groundout to first base. Hammel struck out Harper with four consecutive sliders, the last of which bounced into the dirt. Harper swung over it, then gently tossed his bat, helmet and batting gloves into a pile.

The Cubs ripped the game open in the ninth, when Williams may have been overthinking his options. He removed Ross Detwiler when the Cubs pinch hit with right-handed batter Mike Olt, who this season is 9 for 49 with 15 strikeouts against left-handed pitchers. Williams still wanted to avoid the matchup, so he brought in Aaron Barrett. The Cubs countered, replacing Olt with lefty Ryan Sweeney, who doubled.

The inning devolved as Barrett issued an intentional walk and a single, then yielded to lefty Jerry Blevins. He ended up facing right-handed cleanup hitter Starlin Castro, who roped a two-run single.

“You just can’t dwell on anything,” Roark said. “They beat me twice in a row. Let’s move on to the next one.”