Joe Nathan opted for Tommy John surgery:

Nathan played catch with pitching coach Rick Anderson this morning. It was Nathan’s first throwing session since he suffered a significant tear of his ulnar collateral ligament on March 6.

“Didn’t go like we hoped,” Nathan said. “We knew it was a long shot, but what this did do is clear my head. Definitely was no gray area. Definitely was on the black side, where it didn’t go as well as we like, and we know now we’re going to have to go in and get some surgery done, get this thing fixed up.”

Nathan is hoping to return for opening day in 2011. Now the Twins need to decide what to do about the closer role.