The deal was not announced until after the 4 p.m. deadline, and Nationals General Manager Mike Rizzo admitted it was finalized “extremely close” to the drop-dead moment.

“But we finally agreed to a level of prospects and a deal that was something that appealed to us,” Rizzo said. “And we made the deal.”

AD

Watson is a 20-year-old left-hander who was 6-4 with a 4.35 ERA at Low-A Hagerstown and has averaged more than a strikeout per inning. Kintzler is under control through just this season, and the Nationals will owe him roughly $1 million in prorated salary. His exact role with Washington remains to be seen, and Rizzo said he doesn’t expect to name one man as closer yet.

AD

“I think we’re going to get a feel for how the bullpen comes together and how they jell, what roles we would like to see them in,” Rizzo said. “We’ve got two months left in the regular season to figure out which is the best way to attack the bullpen, what are guys most comfortable in.”

The Nationals designated right-hander Jimmy Cordero for assignment to clear room for Kintzler on the 40-man roster, but his arrival will almost certainly create a somewhat surprising logjam of veteran right-handers. Shawn Kelley is on a rehabilitation assignment and is expected back fairly soon. Joe Blanton, to whom the Nationals committed $4 million this season, settled down after a rough first two months.

AD

Matt Albers has been the most reliable member of the Nationals’ bullpen throughout the season. But with Ryan Madson and Sean Doolittle now in the fold, and Matt Grace, Enny Romero and Oliver Perez pitching well enough to stay, the Nationals will have decisions to make — though they will be welcome to a bullpen that has had far too few options for much of the season.

AD

Kintzler is an unorthodox closer. Though he is third in baseball with 28 saves (in 32 opportunities), Kintzler has the sixth-lowest strikeout rate (5.36 per nine innings) of more than 150 qualified major league relievers. He relies on soft contact, not swings and misses, something that can cause late-inning angst when balls fall in, but does contrast with the more strikeout-heavy ways of Doolittle and Madson.

“They get their outs in different ways,” Rizzo said. “And I think what we were looking to do was shore up the back end of the game and make the game shorter. I think we’ve done that with Brandon, Ryan and Sean.”

AD

The Nationals began the final day of baseball’s uninhibited trading season having added a great deal to their first-place roster already. They previously acquired two elite relievers and brought on experienced depth for their bench.

AD

They traded for Madson and Doolittle, and in so doing, stabilized their previously shaky bullpen. Friday, they acquired infielder/outfielder Howie Kendrick from the Phillies, thereby bolstering a bench that will look particularly formidable once injured players Jayson Werth, Trea Turner and Michael A. Taylor return.

As of Monday morning, the Nationals were still considering adding more, particularly to that bullpen — surer now than it was before. Justin Wilson was among the small group of players in which the Nationals took great interest during the past month, but he landed with the Cubs in a deal late on Sunday night. Padres reliever Brad Hand stayed put. Former Cardinals closer Trevor Rosenthal and Orioles closer Zach Britton did, too. While Madson and Doolittle have ninth-inning experience, neither is a true closer. Whether the Nationals believe they have found one in Kintzler, who could also fare well in setup duties, remains to be seen.

AD

“It’s a continual experiment sort of depending on the production on how the guys do, their performance,” Nationals Manager Dusty Baker said. “The better a guy performs, the more I can slide him into a certain place or certain time. Or I’ll see which guys feel comfortable at certain parts of the game.”

AD

With their starting lineup mostly set, and a firm organizational belief that Werth, Taylor and Turner will return in plenty of time for October, the Nationals did not add any more position players. Kendrick fills their one bench hole, the right-handed bat, and can play a variety of positions. As long as they believe Stephen Drew will be healthy again soon — or, given the way Wilmer Difo is hitting, even if they don’t — they should not have to add an infielder.

After Erick Fedde allowed five earned runs in four innings Sunday, and given Edwin Jackson’s inconsistencies, the Nationals do have a hole in the back of their rotation. But despite the fact that Stephen Strasburg went on the disabled list with a nerve impingement in his elbow, the Nationals did not trade for a starter. Asked if they tried, Rizzo said “no. We didn’t.”

The Nationals added roughly $7 million in salary at the deadline, $5.6 million in the trade for Doolittle and Madson and the league minimum for Kendrick, with the Phillies paying most of his salary down as part of that deal. They also added nearly $12 million for 2018, to which neither Kendrick nor Kintzler will contribute. Always salary conscious, the Nationals did not spend exorbitantly, but did add salary, something they have not always done in deadlines past.

AD

AD

Washington can still make deals after the nonwaiver deadline, but its targets must pass through waivers to do so. The Nats traded for Matt Thornton in August 2014. They acquired lefty Marc Rzepczynski in late August last season. Both factored in their playoff bullpens. Moves could still be on the way.

Bs of about 4:05 p.m. Eastern — because word of the Kintzler deal did not come until slightly after that 4 p.m. deadline — the Nationals had replaced three of the seven members of their bullpen and one member of their bench in one of their more active deadlines yet.

Jorge Castillo in Miami contributed to this report.