Kelvin Herrera will give the Nationals the closest thing they’ve ever had to a “super bullpen.” (Michael Ainsworth/Associated Press)

The Nationals jumped out ahead of the trade market Monday night, acquiring closer Kelvin Herrera from the Kansas City Royals in exchange for minor leaguers Blake Perkins, Kelvin Gutierrez and Yohanse Morel. In so doing, they compiled the closest thing they have ever had to a “super bullpen,” adding a closer with World Series experience to their heavily worked back three of Brandon Kintzler, Ryan Madson and Sean Doolittle while keeping one of the best relievers likely to be available at this year’s deadline away from rivals who would likely have pursued him.

The Nationals will do all this without surrendering any of their most prized prospects, which makes sense given they are effectively trading for four-plus months of a pitcher who throws an inning at a time and will become a free agent after the season. They will pay Herrera the remainder of his $7.9 million dollar salary, but in a season in which they are already planning to cross the luxury tax threshold, the bump does not make a dramatic difference.

General Manager Mike Rizzo did not discuss the deal Monday night, but it continues his annual tradition of acquiring big-name relievers in midsummer deals, adding Herrera’s name to a list that includes Kintzler, Madson, Doolittle, Mark Melancon, Jonathan Papelbon and others. This deal comes weeks ahead of when Rizzo made those past moves, indicating that the Nationals identified the reliever they felt they needed and saw no reason to wait.

“For the front office to send a message to us this far ahead of the deadline, to try to get us some help in the bullpen, I think it’s one of those situations where in April and May, the bullpen as a whole had a really heavy workload. You saw Madson and Kintzler land on the DL because of that,” Doolittle said. “It’s almost their way of saying, ‘Here’s some help. Here’s some reinforcements.’ ”

Herrera is 28 years old and pitched to a 1.05 ERA in 27 games for Kansas City. His fastball sits in the high-90s. He is a two-time all-star who has closed and served as a setup man on World Series teams. He will not close for the Nationals. That job will remain in the hands of Doolittle, who is compiling an all-star season of his own with 18 saves and a 1.47 ERA.

“For me, we have an all-star closer right now,” Martinez said. “So [Herrera] will be asked to do some different things.”

Rizzo came down to the clubhouse in the second inning of Monday night’s second game and tracked Doolittle down in the weight room to tell him about the deal in person, so Doolittle wouldn’t find out later from his phone.

“He grabbed me and just wanted to say, ‘Hey, you might see something later . . . I wanted you to hear it from me. We have a lot of confidence in you. We just think this is going to give us some depth, give us some options. We had an opportunity to make a move to better our bullpen, and we took it,’ ” Doolittle said. “It was awesome that there was that transparency and that communication, and obviously it’s awesome that they’re looking to help us out.”

That the Nationals acquired Herrera without touching any of their top-rated prospects speaks both to the depth of their system and the nature of the deal. Gutierrez is a 23-year-old infielder who is hitting .274 for Class AA Harrisburg, a high-contact type of whom the Nationals thought highly. He entered the season as their 12th rated prospect, according to Baseball America.

The Nationals drafted Perkins out of high school in the second round of the 2015 draft, seeing potential in a smart player who was, at the time, a toolsy teenager. He is now 21, hitting .236 with a homer for Class A Potomac, ranked as the 11th-best prospect in their system. Morel is 17, currently pitching with the Nationals’ Dominican League team, and can touch 95. The Royals are betting on their evaluators in this deal and, in so doing, making the kind of deal that netted the Nationals hidden gems like Tanner Roark, under-the-radar types in whom they see something they think others missed.

Because the Nationals did not touch their top prospects in the deal, they have an arsenal of appealing talent from which to deal for a starter at the trade deadline, should they decide to do so. In Herrera, the Nationals address their most glaring annual need — more bullpen talent — though the need might have been less glaring this year than in years past. They are overflowing with position players. They could use some insurance in the starting rotation, particularly with Stephen Strasburg and Jeremy Hellickson out with injury.

But the Nationals still have a month to plot further deadline deals. Herrera’s arrival will bring more imminent decisions. As it stands, the Nationals were going to have to send someone out of their bullpen Tuesday to bring up whoever will start the series opener against the Orioles. Once Herrera arrives, they will need to send out someone else. Wander Suero and Tim Collins have options, though Collins has enough service time to decline an assignment, and both have pitched well. Justin Miller has proven himself a reliable option in big spots despite two rough outings recently. Matt Grace has no options remaining, so designating him for assignment would mean subjecting him to waivers. He might not clear them. Clubhouse staple Shawn Kelley is in the final year of a three-year deal worth $15 million and has struggled at times this season, allowing five homers in 14 innings. Making room will not be easy, though those who might lose setup work to Herrera — like 37-year-old Ryan Madson — seem more than willing to delegate.

“Let the old horse rest a little bit,” Madson said. “He can let me pitch every once in a while, and I’ll be fine.”

Still, short-term complications do not overshadow the long-term implications of this deal, which give the Nationals the most loaded bullpen they have had in years. If they carry the traditional seven relievers, the Nationals could operate a bullpen in which Miller is the fifth option, Solis the sixth and one of the remaining pitchers the seventh. They are deep and deep in players with closing experience. Herrera has also pitched in and won a World Series. The Nationals hope that experience will become relevant.

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