LAS VEGAS -- The major pieces of their bullpen now in place, the Mets on Thursday set about the business of filling out the rest of it.

The Mets claimed right-handed relievers Darren O'Day and Rocky Cherry in Thursday's Rule 5 Draft, and they will invite both to compete during Spring Training for a spot in the bullpen. Those moves came one day after the Mets acquired relievers J.J. Putz and Sean Green from the Mariners and finalized a three-year contract with free-agent closer Francisco Rodriguez.

"We'll bring them into camp and see what happens," Mets general manager Omar Minaya said of his new players. "It gives us flexibility. We'll see who has a good camp and who doesn't."

The Mets selected O'Day, 26, from the Angels with the 15th overall pick in the Draft. O'Day, whom Minaya compared to former Mets reliever Chad Bradford with his dropdown delivery, produced a 4.57 ERA in 30 appearances with the Angels last season. Yet a torn labrum undermined his success and caused the Angels to remove him from their 40-man roster after season's end, thus making him eligible for the Rule 5 Draft.

The Mets then selected Cherry, 29, from the Orioles with the 21st pick in the Draft. Cherry produced a 6.35 ERA last season in Baltimore and a 5.77 mark over parts of two seasons with the Orioles and Cubs.

"He's got a good arm," Minaya said of Cherry. "We thought we'd add him into the mix."

The Rule 5 Draft, an annual event at the Winter Meetings, allows clubs to select players not protected by status on a 40-man roster for the cost of $50,000. Those players then must spend the entire season on the receiving team's 25-man active roster, barring time on the disabled list, or be offered back to their original club for $25,000.

The Mets selected another right-handed reliever, Steven Register, from the Rockies in last year's Rule 5 Draft. Register spent nearly all of Spring Training with the Mets before New York offered him back to Colorado.

The Mets also employ the foremost Rule 5 Draft success story of all time, Johan Santana. The Twins selected Santana from the Astros in 1999, and he shortly thereafter flourished into one of the top pitchers in baseball. Last January, having won the American League Cy Young Award in 2004 and '06, Santana was traded to the Mets by the Twins.