A's Top Pitching Prospect Wei-En Lin Suffers Season-Ending Injury

He pitched in 12 games this year

Feb 20, 2026; Mesa, AZ, USA; Athletics pitcher Wei-En Lin (81) poses for Photo Day at HoHoKam Stadium. Mandatory Credit: Rick Scuteri-Imagn Images | Rick Scuteri-Imagn Images

The Athletics just received some devastating news on the status of one of the organization's top pitching prospects, left-hander Wei-En Lin.

Lin, the A's No. 4 prospect for 2026 on MLB Pipeline, is expected to undergo Tommy John surgery, according to MLB.com's Martín Gallegos. As a result, the 20-year-old will be sidelined for the rest of the 2026 season. And due to the lengthy recovery timeline typically associated with elbow injuries for pitchers, the southpaw could miss a large chunk of the 2027 season as well.

The Taiwanese pitcher signed with the A's in 2024 and made his professional debut last year. Lin posted a 3.72 ERA in 26 games (13 starts) across three minor league levels in 2025, racking up 117 strikeouts in 87 innings. In 2026, the young lefty made 12 starts and had a 3.23 ERA with 54 strikeouts in 53 innings pitched across Double-A and Triple-A.

How have other A's pitching prospects performed so far in 2026?

Jul 28, 2025; West Sacramento, California, USA; Athletics 2025 first-round draft pick Jamie Arnold walks onto the field before the game against the Seattle Mariners at Sutter Health Park. Mandatory Credit: Sergio Estrada-Imagn Images | Sergio Estrada-Imagn Images

With Lin on the shelf for the foreseeable future, the A's pitching depth in the upper levels of the minors undoubtedly takes a hit. But the A's still have a couple of noteworthy prospects in their farm system.

Left-hander Gage Jump is still technically the A's No. 3 prospect on MLB Pipeline, but the 23-year-old was called up for his MLB debut at the end of May. And so far, he's looked like a future ace of the A's rotation, posting a 2.04 ERA through his first six big league starts.

Once Jump graduates from the prospect rankings, right-hander Kade Morris will likely move into the A's top-10 list. The 24-year-old was promoted to the majors earlier this month, but he struggled in his only MLB start so far, giving up nine runs in four innings against the Houston Astros. In Triple-A this year, Morris has a 4.41 ERA through 14 starts.

Meanwhile, the A's highest-ranked pitching prospect is left-hander Jamie Arnold. The 2025 first-round draft pick has a 4.24 ERA through his first 14 Double-A starts with 73 strikeouts in 70 innings to begin his minor league career. In June, though, the 22-year-old has posted a 2.31 ERA in four starts.

With Jump in the majors and Lin on the sidelines, even more of the spotlight will be on Arnold now as the top minor league arm to watch in the A's farm system.