FORT MYERS, Fla. — Twins closer Joe Nathan told reporters Sunday morning that he will undergo Tommy John ligament replacement surgery on his right elbow as soon as possible.

Nathan played a game of catch this morning with pitching coach Rick Anderson but felt stiffness in his right elbow.

“It didn’t go like we hoped,” Nathan said. “We knew it was a long shot, but what this did do is  clear my head. There was definitely no grey area.”

Nathan was diagnosed with what the Twins called a “significant” tear in his ulnar collateral ligament on March 8, two days after he left a spring exhibition game against the Red Sox with stiffness in the elbow. Nathan held out hope that he could rehab the injury but said after the game of catch that it was not possible.

The pitcher’s intention is to have the surgery done within the next week, although he said he
hasn’t decided exactly when that will be or who will perform the surgery. The estimated recovery time is 12 months and Nathan said he’s looking to be ready for Opening Day 2011.