Masahiro Tanaka (RAK) got his right flank checked out at a hospital on Monday and was diagnosed with a strain in his right pectoral muscle. The strain is expected to require about three weeks for a full recovery.
Tanaka will not travel with the team to Chiba and will instead stay at home for rest. It seems the team wants to see how he does over the next couple of days before making a decision on what to do.
Clarification: Tanaka will likely be taken off the active roster on Tuesday, but the club will keep a close eye on him over the next couple of days before deciding how much time he'll really miss. Based on most of the headlines, it would seem his season is more or less done.