Athletics right-hander Zach Jackson went unclaimed on waivers after being designated for assignment and has been assigned outright to Triple-A, per the team’s transaction log at MLB.com. Jackson has fewer than three years of service time and does not have a prior outright in his career, so he can’t reject the assignment in favor of free agency. He’ll head back to Las Vegas, where he’d opened the season, and hope to pitch his way back onto the big league roster.
The 29-year-old Jackson has pitched 66 innings with Oakland over the past two seasons and turned in a sterling 2.86 ERA in that time. A look under the hood reveals more concerning issues, however, most notably including a grim 15.2% walk rate (to say nothing of a sky-high 14 wild pitches). Jackson has fanned a whopping 31.9% of his opponents in that time as well, but his lack of command is a clear red flag. He’s also benefited from seeing a minuscule 2.6% of his fly-balls become home runs — about one-fifth of the roughly 12% league average. Metrics like xFIP and SIERA, which normalize HR/FB ratio, peg Jackson at 4.23 and 3.79, respectively.
A flexor strain limited Jackson to 18 innings last year, and he’s had a tough return. In 8 1/3 spring innings, he yielded seven runs (six earned) on six hits and three walks. He’s continued to struggle through his first three appearances in Vegas, serving up four runs in two innings of work. More alarming than the runs allowed, however, are the eight walks he’s issued despite facing just 16 hitters on the season thus far.
It’s likely there’s some rust for Jackson following that 2023 injury, but he’s presumably in good health. The A’s didn’t place him on the minor league injured list, and injured players can’t be placed on outright waivers. If he can get back on track in Vegas, it wouldn’t be a surprise to see him back in the majors. The Oakland bullpen is lacking in established relievers, currently including five pitchers with under a year of MLB service time and a pair of veteran journeymen looking to rebound (Austin Adams, T.J. McFarland).