While a student at National Taiwan Sport University, Chen signed a 3-year ikusei (development) contract with the Yokohama BayStars of Nippon Professional Baseball (NPB) in February, 2011.[2] Chen underwent Tommy John surgery in 2012[3] and did not appear in a game that season, returning late in the 2013 season. On July 11, 2014, Chen was promoted from development player to a regular team contract (with his uniform number changing from 118 to 59)[4] and made his official professional debut three days later at Mazda Zoom-Zoom Stadium versus the Hiroshima Carp. However, his debut game did not go well, and soon after Chen was demoted to the ni-gun squad and subsequently was released from the team in October of that same year.
Chiba Lotte Marines
Chen joined the free agent player tryouts for the Chiba Lotte Marines of NPB in November, 2014, and after a successful tryout was signed to a one-year, 6 million Japanese Yen contract in December.[5]
In the 2015 preseason, Chen earned a spot in the Lotte starting rotation and made his debut with the team in the opening series in Fukuoka versus the defending champion SoftBank Hawks. That start ended in a loss, and for the first few months of the season Chen split time between the ichi-gun team and the ni-gun team in Urawa. However, by the summer Chen was back with the ichi-gun team on a permanent basis, and in the push for a Climax Series spot he proved invaluable, finishing the regular season with 14 2/3 consecutive innings pitched without an earned run.[6]
Chiba Lotte resigned Chen for the 2016 season on January 6, 2016, with a 183% salary increase (to 17 million yen).[7]