Fukuoka Daiei Hawks lefty Tsuyoshi Wada, who left the mound in the fifth inning due to soreness in his left thumb a day earlier, on Wednesday was diagnosed with arthritis at the base of his thumb.
According to baseball sources, the 23-year-old will refrain from having bullpen sessions for the next week and most likely skip his scheduled start in a preseason game against the Yomiuri Giants next Tuesday.
Wada won the Pacific League rookie honors last season after going 14-5 with a 3.38 ERA in 26 games.