Minneapolis, MN (Sports Network) - Minnesota Twins closer Joe Nathan reportedly has a significant ligament tear in his right elbow.

The Minneapolis Star-Tribune said tests revealed damage to the ulnar collateral ligament.

According to the report, Nathan will rest the elbow for two weeks to allow swelling in the area to subside. He will then try to strengthen the elbow before trying to pitch.

If rehab does not work, surgery will be necessary.

Nathan faced one batter Saturday in a spring training game against Boston and left the mound after experiencing tightness in the elbow. He left Florida and traveled back to Minnesota on Sunday for tests.

The 35-year-old Nathan is coming off a franchise-record 47-save season in 2009. He threw to a 2.10 earned run average in 70 appearances but had to have bone spurs and loose bodies removed in his right elbow following the season.

Over his 10-year career, Nathan has compiled 247 saves to go with a 2.75 ERA in 533 games -- 29 starts.

03/09 09:40:42 ET