The Rangers’ free-agent additions to the rotation this winter consisted of Andrew Cashner and Tyson Ross, but following a setback for Cashner in his bout with biceps tendinitis, neither of those right-handers will be ready for Opening Day. In light of that news, MLB.com’s T.R. Sullivan reports that the Rangers aren’t ruling out the addition of a free-agent starter (Twitter links). More specifically, he adds that some club officials admitted to him that they’re missing right-hander Colby Lewis. Jeff Wilson of the Fort Worth Star-Telegram tweets something similar, noting that the Rangers aren’t sure where Lewis is at from a training standpoint but adding that it “sounds like he’s entered their thinking.