It’s been an impressive turnaround, but the Washington Nationals still have a glaring weakness.

A 28-11 stretch of play is nothing to scoff at, especially when it follows an abysmal 19-31 start to the season. Yet despite the Nationals’ strong play, their bullpen issues have continued to be an ugly stain on what has become an exciting campaign.

The eighth inning has been a revolving door of hopeful set-up men; each earns the opportunity with an effective appearance or two, only to blow a close lead and be relegated back to the middle innings.

It appears 42-year-old midseason acquisition Fernando Rodney (2 ER in 5.1 IP) might be the answer, but even he — like closer Sean Doolittle — can’t pitch every night. Doolittle himself admitted he’s “a little tired” from his heavy workload this season.

Similar to the circumstances under which Washington acquired Doolittle in the first place, the Nationals need bullpen reinforcements. It was difficult to justify them making any additions earlier this year when they sported one of the worst records in baseball, but the team has salvaged its season and thrust itself right into the National League playoff race.

The Nationals probably needs at least two or three relievers to fortify their ’pen enough to make them World Series contenders, so here are five bullpen arms the Nationals should target ahead of the July 31 trade deadline.

1. Will Smith – SF

36.1 IP, 1.98 ERA, 2.02 FIP, 13.1 K/9, 0.798 WHIP, 6.63 K/BB, 23 saves

Sergio Estrada-USA TODAY Sports

If one thing’s for sure, the Nationals are going to need a slam-dunk acquisition to fill the void that’s become the eighth inning. Will Smith might not be the biggest name around the league, but the 29-year-old lefty has been electric as the San Francisco Giants’ closer this season.

Smith, a first-time All-Star, ranks second in the NL in FIP — a metric similar to ERA that adjusts for park effects and team defense — and strikeout-to-walk ratio, trailing only San Diego Padres closer Kirby Yates in both categories.

He has a modest salary of $4.225 million this season, which would be prorated based on when he’s traded, and is a free agent at the end of the year. The Giants are certainly motivated to deal him too, with the team out of contention and holding very few trade assets.

What makes Smith even more appealing is the fact that he could be packaged with one of his set-up men in a deal similar to the one Nats GM Mike Rizzo pulled off in 2017 when he acquired Doolittle and Ryan Madson from the Oakland A’s. Sam Dyson (2.30 ERA, 0.884 WHIP) and Tony Watson (3.38 ERA, 1.154 WHIP) both have prior closing experience and are signed to cheap team options for 2020.

2. Shane Greene – DET

33 IP, 1.09 ERA, 3.72 FIP, 9.27 K/9, 0.879 WHIP, 3.40 K/BB, 22 saves

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Regardless of whether or not the Nats keep the left-handed Doolittle in the ninth or bump him down to the eighth in favor of a midseason acquisition, they’re going to need a righty to complement him in the later innings.

For that, look no further than Tigers right-hander Shane Greene. The former 15th round pick has the best ERA in baseball among relievers with at least 30 innings this season. His velocity is a tick lower than it’s been in previous seasons, but he’s made great use of his sinker to produce ground balls at the best rate of his career.

Greene is under contract through next season, when he’ll likely get a nice pay raise in arbitration. He’s owed less than $2 million the rest of this year, however, meaning the Nats could stay under the luxury tax with enough room to make another move. Cot’s Contracts pegs Washington at $7.1 million beneath the threshold.

3. Alex Colomé – CHW

35.2 IP, 2.02 ERA, 3.99 FIP, 6.81 K/9, 0.701 WHIP, 2.70 K/BB, 20 saves

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One of the best relievers in baseball at inducing weak contact, White Sox closer Alex Colomé has taken his game to a new level this season with an other-worldly 0.701 WHIP. He leads the AL with that figure and ranks second to Josh Hader (0.651) for the MLB lead among relievers.

Among the pitchers on this list so far, Colomé boasts the best track record. All 116 of his career saves have come over the last four years, including the league-best 47 he accrued for the Tampa Bay Rays in 2017.

He’s also being paid the most of the group, earning $7.33 million this season with another year left on his rookie deal. The Nats may stay away from him for that reason, depending on how many relievers they hope to add at the deadline.

4. Ken Giles – TOR

31 IP, 1.45 ERA, 1.49 FIP, 15.39 K/9, 1.000 WHIP, 5.89 K/BB, 13 saves

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Ken Giles hasn’t had many save opportunities pitching in Toronto, but don’t let that fool you. He’s been one of the most prolific strikeout pitchers in baseball this season.

The former Houston Astro has struck out 43.4% of the hitters he’s faced this season. If that sounds good to you, that’s because it is. It ranks second in the majors behind only Hader (51%). The Nats have a few relievers capable of striking guys out, but nobody in that bullpen can match the swing-and-miss rate of Giles.

He’ll be owed a prorated amount from his $6.3 million salary and, like both Greene and Colomé, is under contract through next year.

5. Hansel Robles – LAA

42.2 IP, 2.74 ERA, 2.92 FIP, 8.86 K/9, 1.102 WHIP, 3.82 K/BB, 12 saves

Jerome Miron-USA TODAY Sports

The Angels are technically still in the running for an AL Wild Card spot, but it’s going to be an uphill battle now six and a half games back and a game under .500. If they do decide to sell, Hansel Robles will instantly become one of the more attractive trade chips on the market.

Robles is signed to a bargain $1.4 million salary this season and still has two years left on his rookie deal. The Dominican native is only 28 years old and Washington knows him well after he spent three and a half years with the New York Mets.

Another team with several quality relievers, the Angels could package Robles with one of his set-up men in Cam Bedrosian (3.56 ERA, 1.163 WHIP) or Ty Buttrey (2.57 ERA, 1.214 WHIP). If they’re set on acquiring multiple relievers in one trade, the Nationals could turn to Los Angeles if they lose out on a deal for Will Smith and one of his set-up men in San Francisco.