Katsuya Kakunaka ended batting practice early on March 12 and did not play in the exhibition game against Yokohama at Yokohama on the same day because of pain in the right side of his back. His condition does not appear to be serious.
Source: Sponichi 3/12/2017
[UPDATE 3/14 @ 2:57am]
Kakunaka will be taking things slow for a couple of days.
Source: Nikkan Sports 3/13/2017