ATLANTA -- Recent years have shown that general manager Mike Rizzo is not afraid to get a jump-start on the trade market to address the Nationals' biggest need before the Trade Deadline. One year ago, he acquired Kelvin Herrera from the Royals in the middle of June. In 2017, he waited until the middle of July to trade for both Sean Doolittle and Ryan Madson from the A's.

Even though the Nationals biggest need -- their bullpen -- has been painfully obvious for months, Rizzo has had to contend with what he called a “late developing” trade market, with just nine days to go until the July 31 Trade Deadline, the lone deadline in MLB this season.

“I don’t know if that’s because of only the one Trade Deadline,” Rizzo said from the visitors' dugout Sunday in Atlanta. “Especially in the National League, there are a lot of teams that are bunched together. But I do see it as a later-forming market.”

Rizzo provided some insight into his plans ahead of the Deadline, starting with the obvious, that the Nationals will be seeking additions to their bullpen and focusing on relievers with years on their contract beyond the end of 2019. As MLB.com reported this weekend, Washington has been connected to relievers such as Shane Greene of the Tigers, Sam Dyson of the red-hot Giants and Jake Diekman of the Royals.

“There’s always a balance you have to draw between what the acquisition cost is, what are you getting back and that type of thing,” Rizzo said. “But it’s always preferable for us to go after a guy that will be with us for a couple years rather than a guy who will be with you for a couple months.”

Although Rizzo said he might prefer a reliever that is more than a rental, he did say he was willing to be flexible for a deal that made sense. One thing he was certain on, however, is that the Nationals would not be willing to exceed the Competitive Balance Tax to do so.

“We don’t want go to past the CBT,” Rizzo said. “So we’re going to be cognizant of that in any deals that we make.”

It’s unclear how much wiggle room that gives Washington. According to Cot’s Baseball Contracts, the Nats are just about $6 million under the threshold, a number that does not factor in end-of-season incentives.

And if the Nats are unable to take on much salary, opposing teams usually ask for higher prospects in return. After years of Deadline deals for relievers, the Nats’ Minor League depth has thinned, and so far they have also been reluctant to deal top prospect Carter Kieboom, the 20th-ranked overall prospect, according to MLB Pipeline.

Since the Nats became contenders, however, Rizzo has never allowed a Trade Deadline to pass without addressing his team’s biggest weakness. And for two months, Washington has been the hottest team in baseball. The Nats have given him a reason to go for it, and he rarely passes on the opportunity.

The bullpen has found competence recently, with Wander Suero and Tanner Rainey developing into effective, though inconsistent, relievers late in games in front of Doolittle with veterans Javy Guerra, Fernando Rodney and Tony Sipp helping to settle the 'pen as well. But the Nats could still use a massive upgrade to help sure up the end of games.

“I think that there’s several guys that developed into guys that are long-term assets for us,” Rizzo said. “I think we’ve seen Suero have moments of brilliance, and have Rainey and those guys. I think those guys are showing that they are impactful guys for us in the bullpen. I think they’re like a lot of relief pitchers out here, who are a little less consistent than we’d like them to be, but they’re learning to go back to back and three days in a row, and to warm up and not get in. They are learning the ropes at the Major League level, and I think they’ve really stabilized us to the point where we feel like we can count on those guys.”

And perhaps the bullpen's recent performance has bought Rizzo some the time to make sure he finds the right deal to complement them.