4. Jen-Ho Tseng
Right-handed pitcher Jen-Ho Tseng was signed as a non-drafted free agent by the Cubs in 2013 and is another example of a failed Cubs pitching prospect. Tseng won the Cubs minor league pitcher of the year award in 2017 after posting a 2.54 ERA over 24 starts. But after making it to triple-A Iowa in 2018, things took a turn for Tseng. In 136 innings pitched, Tseng put up a 6.27 ERA. This was the main reason behind his being designated for assignment in April of 2019 and released by the team the following week. In 2021, Tseng entered the mid-season draft in the Chines Professional Baseball League in Taiwan. He now pitches for the Rakuten Monkeys.