The media learned yesterday that Wei-Ying Chen could be out 8 weeks with a left adductor muscle injury. That means he'll the start of the regular season.
While the Chunichi Dragons haven't made any official statements, Nikkan Sports pieced together information from various sources and found that the injury Chen suffered was actually a lot worse than the club originally thought and will require 6-8 weeks for a full recovery. Worst case scenario would mean a return on 4/12. And chances seem very unlikely that he'll be ready for the start of the regular season.
It does appear as though the injury is improving, but the team still has no idea when he'll be able to start playing catch. And at this point, it's all day-to-day.