Daichi Osera felt some discomfort in his right side during a bullpen session on February 11. His workouts today were adjusted accordingly. He will not be doing any throwing for the time being.
Source: Daily Sports 2/12/2017
[UPDATE 2/16 @ 10:56pm]
Koichi Ogata told reporters today that he will not be taking Osera to Okinawa camp that begins on February 22. His condition is improving, but Ogata does not want to push him too hard. He still wants Osera to be ready for the start of the season.
[UPDATE 3/14 @ 2:55am]
Osera joined the Ichi-gun team for general workouts at Mazda Stadium on March 13. He pitched three scoreless innings in a Kyoiku League game against Hanshin on March 12.
Source: Daily Sports 3/13/2017