Dai-Kang Yoh took a pitch off his helmet during his at bat in the sixth inning of a game against the Softbank Hawks on June 15. The ball hit him as he tried to get out of the way. He fell to the ground, but quickly got up. He was visibly upset and had to be held back as he shouted toward Yuito Mori on the mound. Both benches cleared and the umpired issued a warning.
Yoh was replaced by a pinch-runner. He was taken to a hospital for tests.
Source: Nikkan Sports 6/15/2017
[UPDATE 6/16 @ 9:27pm]
Yoh did not participate in pre-game practices on the field tonight was left out of the starting line-up against Lotte. He was available off the bench, but did not see any playing. His tests at the hospital last night did not reveal any abnormalities. He is considered day-to-day as a precaution.
Source: Sponichi 6/16/2017