Hiroyuki Nakajima took a batted ball off the area near his left wrist while playing defense in the fourth inning against Nippon Ham at Kyocera Dome on April 14. He left the field for treatment and returned, but was later removed from the game as a precaution. He is considered day-to-day.
Source: Sports Hochi 4/14/2016
[UPDATE 4/15 @ 5:44am]
Nakajima was examined at a hospital in Osaka. He told reporters there was swelling, but most likely no abnormalities to the bones.
Source: Sanspo 4/22/2016