Mariners Claim LHP Sean Doolittle off Waivers from Cincinnati

RHP Keynan Middleton designated for assignment

SEATTLE, Wash. — Seattle Mariners Executive Vice President & General Manager of Baseball Operations Jerry Dipoto announced today the following roster moves:

• Sean Doolittle, LHP, claimed off waivers from Cincinnati.
• Keynan Middleton, RHP, designated for assignment.

The Mariners Major League, 40-man, roster remains full at 40-players.

Doolittle, 34, is 3–1 with a 4.46 ERA (19 ER, 38.1 IP) with 18 walks and 41 strikeouts in 45 games with the Reds this season. He has limited left-handed hitters to a .229 batting average this season, compared to a .300 batting average against right-handed batters. He was designated for assignment by Cincinnati on Aug. 24.

Doolittle has made 20 career post-season appearances, pitching in the playoffs in 2012, 2013, 2014, 2017 and 2019. During the Nationals 2019 World Series run, he made 9 post-season appearances and allowed only 2 earned runs in 10.1 innings (1.74 ERA). He made 3 scoreless World Series appearances in 2019 and recorded the save in Game 1. Overall, he holds a 2.42 ERA (6 ER, 22.1 IP) with 3 walks and 23 strikeouts in 20 post-season appearances, while limiting opponents to a .213 batting average against.

Since making his debut in 2012, Doolittle ranks 10th among all active left-handers with 446 career relief appearances. Overall, he is a veteran of 10 Major League seasons with Oakland (2012–17), Washington (2017–20) and Cincinnati (2021), going 26–24 with a 3.19 ERA (154 ER, 434.0 IP) with 98 walks and 504 strikeouts. He made his Major League debut with Oakland on June 5, 2012 vs. Texas.

Middleton, 27, was optioned to Triple-A Tacoma on Aug. 25. He is 1–2 with 4 saves and a 4.94 ERA (17 ER, 31.0 IP) in 31 relief appearances and 1 start this season. He has 19 walks and 24 strikeouts, allowing just a 1.4% home run rate with the Mariners this season.

The right-hander was originally selected by the Angels in the third round of the of the 2013 MLB First-Year Player Draft out of Lane Community College (OR). He made his Major League debut with the Angels on May 5, 2017 vs. Houston. Overall, he has appeared in parts of 5 Major League seasons with the Angels (2017–20) and Mariners (2021), going 7–4 with 13 saves and a 3.84 ERA (54 ER, 126.2 IP) with 59 walks and 120 strikeouts.