Mariners claim two-time All-Star reliever Sean Doolittle off waivers from Reds

The Mariners claimed veteran reliever Sean Doolittle off waivers from the Reds, per a team announcement. Fellow reliever Keynan Middleton has been designated for assignment in a corresponding move. Doolittle was designated for assignment earlier this week.

For the bulk of his career, Doolittle has been an elite reliever. After breaking into the big leagues in 2012, he posted an ERA of 3.23 or lower every year through 2018 (excluding a 2015 campaign in which he logged just 13 2/3 innings due to injury). That run of consistency earned him the closer’s role in Oakland, a job he held after being traded to the Nationals in 2017.

Doolittle has fallen on harder times over the past few seasons. While he posted strong strikeout and walk rates in 2019, an increase in home runs allowed pushed his ERA up to 4.05. The southpaw then missed most of last year’s shortened campaign due to knee and oblique issues. Upon reaching free agency, he signed a $1.5M guarantee with the Reds over the winter.

While he has stayed healthy all year, Doolittle didn’t find enough success to stick in the Cincinnati bullpen over the entire season. His strikeout and walk rates (23.7% and 10.4%, respectively) have dipped to about league-average for the first time in his career. While Doolittle hasn’t been quite as home run-prone this season as he was two years back, his 18.2% ground-ball rate is the lowest mark among the 207 relievers with 30+ innings pitched. That made for a tough fit in the hitter-friendly Great American Ball Park.

Doolittle’s fly-ball-heavy ways are easier to manage in Seattle’s more spacious T-Mobile Park. While Doolittle’s strikeout and walk rates suggest he’s no longer the elite late-innings option he was at his peak, the 34-year-old still looks to be at least an average middle reliever.

Acquiring Doolittle comes with very little risk. The M’s will simply have to assume the remainder of that modest $1.5M deal (approximately $295K). For a Seattle club a mere two and a half games back of the final wild-card spot in the American League, it’s a worthwhile cost to bolster the bullpen depth for the season’s final five weeks. If the Mariners do make the playoffs, Doolittle will be eligible for the postseason roster because he was acquired before Aug. 31.

To make room for Doolittle, the Mariners do run the risk of losing Middleton. A well-regarded relief prospect during his days in the Angels system, Middleton broke into the majors with a very promising rookie season in 2017. By early the following year, he had assumed the closing duties in Anaheim.

Unfortunately, Middleton blew out his elbow in May 2018 and required Tommy John surgery. His stuff didn’t look the same upon his return, and the Angels non-tendered last winter after he spent most of the 2020 campaign at the alternate training site. Seattle jumped in to add the righty on a one-year, $800K guarantee in free agency.

Middleton has logged significant action for Seattle this season but hasn’t recaptured his peak form. Across 31 frames, he’s managed just a 4.94 ERA with a career-low 17.1% strikeout rate and a lofty 13.6% walk percentage. Middleton has actually induced plenty of swinging strikes (14.2%), but they’ve yet to translate into consistent results.

Seattle will now place Middleton on waivers over the coming days. Another team could take a speculative flier in the hope that Middleton’s swing-and-miss stuff and still strong velocity could lead to stronger production moving forward. Any claiming team could keep him under club control through 2023 via arbitration if he figures things out down the stretch.