SEATTLE -- The Mariners made their flashiest free-agent acquisition of this offseason to date on Friday, when the club announced it agreed to a two-year deal with reliever Ken Giles. The deal includes a club option for 2023.

Terms were not disclosed, but the contract is worth a guaranteed $7 million over two years, according to MLB Network insider Jon Heyman, and includes a $9.5 million option with a $500,000 buyout for 2023.

In addition, right-hander Robert Dugger was designated for assignment on Friday.

Giles, 30, will be a major boost to a bullpen that posted an American League-worst 5.92 ERA last season -- but not immediately. The right-hander underwent Tommy John surgery on Oct. 1, so he will likely miss the entire '21 season. The seven-year veteran spent the past three seasons with the Blue Jays, and when healthy, he was among the best closers in baseball.

In 2019, Giles racked up 23 saves and 83 strikeouts in 53 innings, posting a 1.87 ERA and a 244 ERA+, fifth best among regular relievers. He spent his first two MLB seasons with the Phillies from 2014-15, then became the Astros’ closer from 2016-18. He had a 2.30 ERA, 34 saves and a 178 ERA+ in 63 games in '17, when Houston won the World Series championship.

Therein lies a huge part of what Giles can bring to the Mariners: experience, including in the postseason. Giles, who has 115 saves and a 148 ERA+ in his big league career, doesn’t have to bring in leadership, but he carries credibility.

Giles also brings some legitimate heat to a bullpen that has lacked velocity. In ’19, Giles' four-seam fastball averaged 97.9 mph, and he paired it with a slider that generated a 54.4% swing-and-miss rate and had a .190 slugging percentage against, per Statcast.

In 2020, when it was clear that he was experiencing elbow pain, Giles gave up four runs on four hits (including two homers) in 3 2/3 innings over four games before undergoing Tommy John. He continues a trend that Mariners general manager Jerry Dipoto has not shied from: putting faith in pitchers who have had surgery.

Giles becomes the fourth reliever who Seattle has added this offseason that has undergone Tommy John surgery, along with Rafael Montero (a former Rangers closer acquired via trade), Keynan Middleton (a former high-leverage Angels reliever) and Kendall Graveman (who was with the Mariners last year and came back on a one-year deal). All three averaged at least 95 mph on their fastballs last season, which would be a huge boon after Seattle relievers had the second-slowest fastball velocity in 2019, per Statcast.

• Why Montero has clearest path to closing

And don’t forget Andres Muñoz, a flamethrower who has topped out at 104 mph. Muñoz, who was acquired at the Trade Deadline last year, is eyeing a June return from Tommy John.

“We had set a pretty low bar, that our bullpen has really been an area of struggle over these past two years,” Dipoto said when previewing the 2021 season last month. “We feel like we are starting to build some stability into a bullpen that really hasn't been very stable over the last couple of years.”

Investing in Giles’ lost 2021 season has become a more common practice industry wide. Former Mariners left-hander Drew Smyly signed a similar deal with the Cubs ahead of the 2018 season while recovering from Tommy John, and former Angels righty Garrett Richards agreed to a two-year deal under similar circumstances with the Padres in ’19.

More than anything, the Giles signing signals a more pronounced move by the Mariners toward the future. He will almost assuredly not be able to pitch until 2022, but he has been an All-Star-caliber pitcher in the past and occupies a position on the team that will hinge on save opportunities -- which depend on winning.