Johan Santana (shoulder) began throwing off a mound this week. Santana revealed the news himself on Twitter, adding that he feels "great." The veteran left-hander is coming back from a second surgery to repair a re-tear of his shoulder capsule and it's uncertain when he'll be game-ready. Twins general manager Terry Ryan indicated last month that Santana wouldn't be ready to pitch until midseason, but the fact that he's already throwing off a mound suggests he could beat that timetable. The Twins and Yankees are two clubs known to be monitoring Santana's progress.