Stairs is joining the Padres on a minor league deal with an invitation to big league camp. Bob Garber, his agent, confirmed the agreement but declined to specify terms.
Garber said that San Diego general manager Jed Hoyer "aggressively'' pursued Stairs to bring a veteran presence to a young team.
"They're bringing Matt in to be a role player off the bench. But at the end of the day, they wanted him as a veteran around some of the young guys to show them the way a little bit,'' Garber said.
Stairs, 41, is a .264 career hitter with 259 home runs in the big leagues. He hit a dramatic eighth inning homer off Jonathan Broxton in Game 4 of the 2008 National League Championship Series to propel the Phillies into the World Series, but fell off sharply last season, hitting .194 with five home runs for Philadelphia.
Stairs, who spends each offseason as the assistant hockey coach for Bangor High School in Maine, has dropped 31 pounds this winter playing senior hockey and dieting with the Nutrisystem program. He began the offseason at 230 pounds and currently weighs 199. That's the lightest he's been in 15 years.
"He wants to be the next spokesman for Nutrisystem,'' said Garber, who added that he's in the middle of negotiations with the company on a possible endorsement deal for Stairs.
Jerry Crasnick covers baseball for ESPN.com.