Athletics Designate Chen Zhong-Ao Zhuang For Assignment

The Athletics announced that they have selected the contract of infielder Jonathan Ornelas, a move that MLBTR covered earlier. To open an active roster spot, outfielder Colby Thomas has been optioned to Triple-A Las Vegas. In a corresponding 40-man move, right-hander Chen Zhong-Ao Zhuang has been designated for assignment.

Zhuang, 25, was an international signing out of Taiwan in 2021. He didn’t pitch much in the years after signing due to arm injuries. In 2024, he was able to log 86 innings across three levels with an excellent 2.09 earned run average. He struck out 25.2% of batters faced while liming walks to a stingy 3.2% pace. He spent 2025 at Double-A with decent results, though not nearly as dominant as the year prior. He threw 145 2/3 innings with a 4.08 ERA, 23.5% strikeout rate and 5.7% walk rate.

The A’s added him to their 40-man roster in November of last year, to keep him out of the Rule 5 draft. Unfortunately, his first taste of the Triple-A level has been disastrous. He has 59 2/3 innings for Las Vegas this year with a 7.84 ERA. Playing in the hitter-friendly Pacific Coast League might account for some of that but his 14.8% strikeout rate and 9.9% walk rate are both significantly worse than the year prior. That has apparently dropped his stock to the point that the A’s no longer consider him worthy of a roster spot.

He now heads into DFA limbo. A team normally has five days to work out trades after designating a player for assignment but the trade deadline is now just three days away. Perhaps some club is willing to look past this year’s struggles while focusing more on Zhuang’s previous work. Just a few months ago, FanGraphs considered him the #25 prospect in the A’s system.