It's no secret that the A's need to improve their bullpen. Oakland blew 30 saves in 2019, the most of any team in the majors.

With that in mind, here are five free agent relief pitchers the A's could target this offseason:

Will Harris

The A's already know Harris well from his time with the Astros. The 35-year-old has spent the last five years in Houston, posting a sparkling 2.36 ERA and 0.99 WHIP.

The 2019 season was the best of Harris' career. The right-hander went 4-1 with four saves, along with a 1.50 ERA and 0.93 WHIP. He notched 62 strikeouts in 60 innings, allowing just 14 walks.

Harris earned $4.225 million this past season and could be due a raise after his terrific performance. However, at the age of 35, he still figures to be an affordable option for Oakland.

Drew Pomeranz

The former A’s left-handed found tremendous success as a reliever this year after getting dealt to Milwaukee. In 25 games with the Brewers, Pomeranz went 0-1 with two saves, a 2.39 ERA, and a 0.91 WHIP. The 30-year-old struck out an eye-popping 45 batters in just 26 1/3 innings, while issuing eight walks.

Pomeranz pitched for the A's in 2014 and 2015, going 10-10 with three saves and a 3.08 ERA. He spent the first part of last season across the Bay in San Francisco, where he struggled mightily as a starter, going 2-9 with a 5.68 ERA. But once he arrived in Milwaukee, he became a completely different pitcher.

Pomeranz earned $1.5 million this year after making $8.5 million in 2018. His new contract will likely fall somewhere between those figures, making a second A's stint a possibility.

Daniel Hudson

A crucial part of the Nationals' World Series title, Hudson figures to be a hot commodity on the free agent market. The 32-year-old went 9-3 with eight saves and a 2.47 ERA between Washington and Toronto, striking out 71 batters in 73 innings.

Hudson also notched four saves in the postseason, going 1-0 with a 3.72 ERA. The right-hander has a career ERA of 3.83 in 10 seasons, with the first four coming as a starter.

Hudson earned just $1.5 million this year and will be in line for a significant raise. Still, the hard-throwing veteran could be worth it for an A's team in need of late-inning options.

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Joe Smith

Smith was superb in limited appearances for the Astros this season. The veteran right-hander went 1-0 with a 1.80 ERA and 0.96 WHIP in 25 innings, striking out 22 and walking five.

Smith, 35, has a career ERA of 2.98 in 13 major league seasons. The sidearm specialist has been particularly effective against right-handed hitters, limiting them to a meager .215/.278/.308 slash line throughout his career.

Smith just completed a two-year, $15 million deal with Houston and could be available for a similar price this time around. The A's would be wise to at least make an inquiry.

Steve Cishek

Cishek is coming off back-to-back stellar seasons with the Cubs. The right-hander combined to go 8-9 with 11 saves and a 2.55 ERA, registering 135 strikeouts 134 1/3 innings.

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Cishek, 33, has a career 2.69 ERA and 1.15 WHIP with 132 saves in 10 seasons. His sidearm delivery has also been especially successful against right-handed hitters, allowing them to slash just .199/.265/.288 in his career.

Cishek earned $6.5 million each of the last two seasons with the Cubs and figures to get a similar contract this offseason. He could certainly help boost the A's bullpen in 2020.