Washington relief pitcher Drew Storen sits in the dugout after giving up two runs in the eighth inning. (John McDonnell/THE WASHINGTON POST)

Drew Storen jogged from the Nationals Park bullpen to start the eighth inning Saturday night against Philadelphia. The game tied at 3, the situation tense — no different than when he was the Washington Nationals’ closer in 2011 and late last season.

Storen was rested, pitching in the set-up role the Nationals want him to fill, yet one that he has struggled to adapt to. Saturday night, he sputtered again, yielding a walk, two hits and two runs in a 5-3 loss.

The Nationals’ bullpen, a weakness as the season moves past the quarter pole, was at the heart of another loss.

“He’s not been where we want him to be,” Manager Davey Johnson said. “He’s not locating like he usually can. . . . I gotta have him. He’s important to our bullpen. That is a situation where I’m counting on him to do it.”

The loss stung even more because the Nationals’ offense, which has endured dormant stretches, came back twice to forge a tie. But what stood out was the handful of squandered opportunities. The Nationals stranded 11, including two in the eighth that reached with no outs.

Storen has surrendered runs in four of his past seven outings, including two blown saves. Against the Phillies, he benefited from a wacky defensive play from second baseman Steve Lombardozzi, who misplayed a grounder but ended up knocking the ball with his knee to Adam LaRoche for the first out of the eighth.

Storen then walked Michael Young before striking out Ryan Howard looking with a wicked backdoor slider. Right-handed Delmon Young, 0 for 2 with two strikeouts in the game to that point, ripped a single down the right field line, far enough from Bryce Harper to allow the racing Michael Young to score. Domonic Brown followed with a double to center, pushing the Phillies’ lead to 5-3. Erik Kratz fouled out to end the inning, and Storen walked slowly off the mound into the dugout, his ERA up to 5.21.

“Left some stuff over the plate that found its way over there,” Storen said. “Just found some holes. Just giving up too many hits and you can’t do that late in the game.”

Johnson has feared that his unsettled bullpen could affect performances. With Ryan Mattheus on the disabled list with a broken hand, some roles are being adjusted. Storen dismissed that as an excuse for his struggles.

“It’s not a confidence thing,” Storen said. “It doesn’t matter how long you’ve been doing this or what you’ve done in the past. It’s what have you done for me lately? I haven’t done a whole lot. So I’m gonna be unhappy about it regardless, and it’s gonna be fixed.”

Added Johnson: “He’s got worlds of confidence. Again, it’s just making pitches. He was unbelievable in ’11 [when he saved 43 games] in making his pitches. And now he’s trying to right the ship and trying to do too much and not trusting his stuff as well as he should.”

Starter Dan Haren kept the Nationals in the game by giving up three runs over six innings and striking out a season-high 10. Two solo home runs in the second and a run surrendered in the fifth inning put the Nationals in a hole. LaRoche’s homer in bottom of the fifth inning tied it at 3.

“Today, I felt like this all year, my body has been bouncing back real good after starts,” Haren said. “I’m encouraged with the way I’m feeling stuff-wise. Today was about as good as I’ve had all year. Today I just made a couple of mistakes. If I’m throwing like I did tonight, we’ll be good.”

Haren completed the sixth after 88 pitches, but was due up third in the bottom of the inning. Johnson turned to struggling Roger Bernadina, who was hitting .115 entering the game, hoping for some offense. On cue, Bernadina ended the inning with a groundout on the first pitch with Henry Rodriguez warming in the bullpen.

Johnson put more trust in Rodriguez on Saturday than he had in more than a month and a half, the last time he entered a game with the Nationals tied or ahead. Rodriguez, who can be plagued by shaky command, has been eased back this season from elbow surgery in August. Against the Phillies, he rewarded Johnson’s confidence with a scoreless seventh.

In the eighth, the Nats put the first two runners on when Kurt Suzuki reached on a drag bunt and Tyler Moore walked. But Lombardozzi couldn’t put down a sacrifice bunt and instead lined a ball to Phillies shortstop Jimmy Rollins for an out. Pinch-hitter Chad Tracy lined out to left on the first pitch he saw from just-entered Jeremy Horst. Denard Span ended the threat with a lineout of his own. As has been their theme this season, the Nationals have done little with the offensive chances they created.

“It’s baby steps,” Ian Desmond said. “We haven’t been swinging the bats really at all, so to put up 11 hits is good. The next thing we tackle is hitting with runners in scoring position.

The Nationals created a promising situation in the third inning against Phillies starter Jonathan Pettibone. Span singled with one out. Harper then lined a slider for another single into right field. After a Ryan Zimmerman flyout, LaRoche took advantage of the shift used against him. Second baseman Freddy Galvis was playing closer to first base, and LaRoche rolled a ball up the middle where the second baseman would normally play. Span scored and the Nationals trimmed the deficit to 2-1.

Desmond then loaded the bases with a walk. On the first pitch he saw, Suzuki tried to hold up on an 87 mph slider from Pettibone and couldn’t. His check swing softly rolled the ball toward first baseman Howard for an out. Suzuki tossed his bat as he ran.

An inning later, the Nationals took advantage of Phillies miscues. Lombardozzi singled and took second on a throwing error by Rollins. Lombardozzi took third on a wild pitch by Pettibone to Span. Then Span narrowly missed a towering two-run home run into the right field second deck, a ball he crushed but that went right of the foul pole by a few feet. On the next pitch, Span lined a single to right to tie the game at 2.

The Phillies took the lead in the fifth with a two-out rally started by Pettibone’s double. Rollins followed with a liner down the right field line. The ball landed fair by inches and Rollins raced to second as the pitcher trotted home.

Again, the Nationals rallied. LaRoche, who is coming out of his season-opening slump, crushed the first pitch he saw in the fifth inning into the visitors’ bullpen. This month, the first baseman has helped carry the team’s offensive output, hitting .325 with five homers.

The tie lasted untill the eighth, when Storen’s struggles took center stage.

“To me, it’s the same stuff is there,” Suzuki said. “Everything is there. He is throwing the ball good. He’s got some good action on his off-speed pitches. It’s hard to explain. Sometimes it doesn’t go your way. It builds a little bit and people start taking about it. And it’s a tough thing.”