Rivera left Yankees camp on Thursday for San Juan, Puerto Rico, where he will suit up with the Panamanian squad and hold the country's flag during on-field ceremonies. Yankees general manager Brian Cashman said that Rivera would be absent from camp for three days.
The 39-year-old Rivera -- who also did not play in the inaugural 2006 Classic -- is recovering from arthroscopic surgery to shave down an AC joint in his right shoulder.
He threw 30 pitches in a bullpen session at George M. Steinbrenner Field on Thursday, firing 15 from a half-mound and 15 from the rubber.
Rivera said afterward that he was "real pleased" with the session and remains on track to appear in a game within the next two weeks. Yankees manager Joe Girardi has circled March 17 as the date to shoot for.
"That's what we're planning," Rivera said. "Hopefully, the body and arm will feel as it's been feeling. Every day it's getting better and better, and that's a good thing."
Panama opens Classic action against Puerto Rico in a 5 p.m. ET matchup on Saturday.
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.