Ryoichi Adachi was hospitalized with ulcerative colitis in January and missed spring camp. He is making good progress and could join the Ichi-gun team some time next week (ahead of schedule).
Source: Sanspo 4/1/2016
[UPDATE 4/1 @ 10:06am]
Adachi is scheduled to play in his first rehab game at Ni-gun on April 2 against Softbank. He will start three to five games and could make the active roster for the Nippon Ham series that begins on April 12.
Source: Sponichi 4/1/2016