A pair of teams with struggling bullpens open a three-game series when the Arizona Diamondbacks visit the Washington Nationals on Tuesday.

The Diamondbacks led the Atlanta Braves 5-3 entering the seventh inning in the deciding game of a three-game series Sunday. However, the Braves scored once inthe seventh and took the lead for good on Eddie Rosario's grand slam off right-hander Miguel Castro in the ninth.

Arizona has blown 12 saves, tied for sixth most in the major leagues.

"I don't know," manager Torey Lovullo said when asked if Arizona needs to acquire a relief pitcher. "That's not my department. I'm sure that if we put ourselves in a position to be buyers over sellers, the front office is unbelievable at figuring out what those needs are."

In Washington on Sunday, the Nationals were locked in a tight series-deciding game of their own, trailing the Philadelphia Phillies 2-1. With two out and two on in the sixth, Nationals right-hander Andres Machado came on to face Kyle Schwarber and the left-handed hitting slugger homered to right-center to make it 5-1.

The Braves eventually built the lead to 11-1 before a late Washington homer from Ildemaro Vargas accounted for the 11-3 final.

"We try to match up the best we can," Nationals manager Dave Martinez said. "We've made it this far doing a good job (without a left-handed reliever). But we've got to make our pitches. When you've got guys up there like that, you've got to throw strikes, you've got to get ahead, and you've got to finish them off."

Arizona left-hander Tommy Henry (3-1, 3.73 ERA) will oppose Nationals right-hander Jake Irvin (1-3, 5.67) in the series opener.

Henry, 25, has allowed just two earned runs in 12 2/3 innings over his last two starts with a scoreless 1 1/3 innings of relief thrown in between. He pitched seven scoreless innings in a win against the Colorado Rockies on Wednesday, allowing two hits, two walks and seven strikeouts.

He gave up two runs over six innings of a no-decision in his only prior start versus Washington on May 6 at home.

Irvin, 26, has struggled at home during his rookie season. He is 0-2 with a 7.47 ERA in four starts at Nationals Park.

In his last outing, last Tuesday at Los Angeles, he allowed four runs on eight hits over five innings and took the loss. On the plus side, after walking four batters in each of his past two starts, he walked just one against the Dodgers.

"I've been really disappointed with the way I've allowed the free pass in the last couple outings," Irvin said. "I made it a point this week to make sure that didn't happen. One walk is definitely encouraging, but there's still room to grow."

Arizona travels to the East Coast tied for first place with the Dodgers in the National League West, 10 games over .500. The success led to Lovullo receiving a contract extension through 2024.

"The team's been playing this way the entire time from spring training on," Arizona general manager Mike Hazen said. "I think the degree of preparation that we see that goes into this with Torey and with his coaching staff is something that we think is an asset of ours."