Thayer is represented by O’Connell Sports Management, which tweeted the agreement this afternoon.
Thayer, 35, is 11-17 with a 3.47 ERA in seven major league seasons. He’s made 264 appearances, all in relief, with the Rays, Mets and Padres.
The Orioles were in the market for another reliever and expressed recent interest in free agent right-hander Carlos Torres. They also pursued left-hander Antonio Bastardo before he signed with the Mets.
Thayer was 2-2 with a 4.06 ERA and 1.381 WHIP in 38 games with the Padres last season after going 4-5 with a 2.34 ERA and 1.056 WHIP over 70 appearances the previous year. He was designated for assignment in August to make room for former Orioles starter Bud Norris on the 40-man roster.
The Padres signed Thayer as an amateur free agent in 2002 and traded him to the Devil Rays in 2006 as the player to be named later in a deal that included future Oriole Evan Meek and Russell Branyan. Thayer signed with the Mets in February 2011 and the Padres in December of the same year.
Right-handers are batting .252/.287/.378 versus Thayer, and left-handers are hitting .249/.317/.403.
The addition of Thayer gives the Orioles 58 players in spring training, including eight non-roster pitchers. They also have 22 pitchers on their 40-man roster.
Yovani Gallardo could join the group if the Orioles are able to sign him. Talks continue this afternoon and the Orioles are the clear favorites at this point.
Pitching coach Dave Wallace and bullpen coach Dom Chiti are going to stay busy in Sarasota.
Left-hander C.J. Riefenhauser, designated for assignment last week, may not receive an invitation if he clears waivers and is outrighted to Triple-A Norfolk.