The veteran right-hander was assigned to the Rays via a waiver claim for a player to be named later.
Bradford signed a three-year contract with the Orioles as a free agent on Nov. 30, 2006. He currently makes $3.5 million and will make the same in 2009, including various incentives.
"We are excited to add Chad to our bullpen," general manager Andrew Friedman said via a text message. "He gives us a very different look from what we currently have. He's an extreme ground-ball pitcher that should enjoy a lot of success pitching in front of our infield defense."
Bradford, who delivers the ball submarine style, originally was expected to join the team in Seattle on Friday, but now it appears he won't be with the team until Saturday, at which time the Rays will have to make a corresponding roster move.
"Mr. Bradford," Rays manager Joe Maddon said. "It's a very interesting acquisition. You look at this guy's ground-ball ratio -- it's the highest, I believe, in all of baseball right now. Really a durable kind of guy, primarily the kind of guy who gets a righty out, but there are lefties he matches up against. He's been very successful in the postseason. And I've heard he's a great guy, a very positive addition for us."
Bradford, 33, was 3-3 with a 2.45 ERA in 47 relief appearances for the Orioles this season. He has appeared in 68 or more games in five of the past six seasons, and he finished third among American League relievers with 78 appearances for the Orioles in 2007.
"My thought is he's a ground-ball machine, that's what he is," pitching coach Jim Hickey said. "And he's the kind of guy you put in the game to roll one over and try and get a double play."
Not since the Rays had Shawn Camp have they had a pitcher they could go to specifically to get a grounder. In addition, Bradford will likely be used in a setup capacity on occasion, joining the likes of Dan Wheeler, J.P. Howell, and Grant Balfour, who currently set up closer Troy Percival.
The move was well received in the clubhouse.
"I'm excited about him coming here," Wheeler said. "I definitely think he's going to help. No question, different look. He's all the way down, almost like a softball pitcher. He comes in, he throws strikes -- which is huge, makes them put the ball in play. The great thing about that is we have a great defense that's going to work behind him. And I'm looking forward to seeing what he can do to help us out here."
"No hitter really likes to face [a submarine-style pitcher]," Maddon said. "No hitter is like, 'Oh good, Chad's coming in.' ... [Having him] gives us a different look. A different weapon we haven't had."
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.