"It wouldn't be fair for me to say I'm 100 percent and go play for Team USA when I'm not," Nathan said. "It wouldn't be fair for the Twins or Team USA. As hard as it is to have to watch this [event] and know I want to be there, at the same time I know this is the right decision to make sure I'm ready for April 6 [Opening Day]."
Twins general manager Bill Smith said the team first informed Major League Baseball that Nathan might not be able to participate after Wednesday night's game against the Red Sox. Nathan pitched one inning in the contest but after exiting the game he told team trainers of the discomfort he was experiencing.
Although Nathan said his shoulder felt better on Saturday when he threw again, the team felt it was best for him not to rush into game action. So after Nathan consented to stay, the Twins emailed the proper paperwork to Major League Baseball on Saturday and Nathan's withdrawal from the event was finalized on Sunday morning.
"If I went and played for Team USA, I'm basically going to be getting after it every time I go out there," Nathan said. "Staying here allows me to kind of get this thing calmed down and strengthened back up kind of at our pace."
Although the discomfort is keeping him from competing in his second successive Classic, Nathan said that he doesn't believe it will be a prolonged problem.
"I'm not worried about it being a major concern," Nathan said of the discomfort. "I guess it's news because of the World Baseball Classic tournament going on and I'm not able to attend."
Although his shoulder flared up during Wednesday's game, Nathan said that he first experienced some discomfort during the offseason.
"I didn't really think much of it," Nathan said. "It's always kind of uncomfortable coming back and starting to throw. But when I got here and started doing everyday stuff, it kind of flared it up a bit. The good thing is I was able to go in and tell them early, and it didn't get too serious."
Nathan threw a bullpen session on Sunday and pitching coach Rick Anderson reported that everything went as expected. The closer will throw a side session on Tuesday and will then pitch on Thursday in an intrasquad contest. With Spring Training lasting an extra week due to the World Baseball Classic, the Twins feel they have the time to take it easy with Nathan.
"He feels good, but that's the way we're going to keep it," Twins manager Ron Gardenhire said. "After something like this, it's scary. You just don't send your closer to let him do that. He's disappointed but he also understands that it's the right thing to do. He'll stay here and make sure we can take care of this.
Five other Twins who were in big league camp are still scheduled to take part in the World Baseball Classic: Luis Ayala (Mexico), Nick Punto (Italy), Luke Hughes (Australia), and Justin Morneau and Jesse Crain (Canada).