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12/12/11 5:20 PM EST

Mets claim Hefner, invite Olson, May to camp

NEW YORK -- The Mets announced Monday that they have claimed right-handed pitcher Jeremy Hefner off waivers from the Pirates and added him to their 40-man roster. The team has also signed left-handed pitcher Garrett Olson and catcher Lucas May to Minor League contracts, and invited both to Spring Training.

Hefner, 25, posted a 9-7 record and a 4.98 ERA for San Diego's Triple-A Tucson affiliate last season, ranking sixth in the Pacific Coast League with 120 strikeouts in 157 1/3 innings. The Pirates scooped up Hefner after the Padres designated him for assignment following the season, only to cut him less than a month later to make room for other acquisitions.

With the addition of Hefner, New York's 40-man roster is now full, meaning the team will have to cut at least two players to make room for relievers Jon Rauch and Frank Francisco, once those free-agent signings become official later this week. Non-tendering catcher Ronny Paulino prior to Monday's deadline would clear one spot. Other players at risk include pitchers Armando Rodriguez and Josh Stinson and outfielder Mike Baxter.

The Mets originally drafted Hefner in the 46th round in 2004, and again in the 48th round in '05, but the right-hander declined to sign on both occasions. Ultimately attending Oral Roberts University and signing with the Padres as a fifth-round pick in 2007, Hefner won San Diego's Minor League Pitcher of the Year Award the following season.

Olson, 28, made the Pirates' Opening Day roster and allowed one run over 4 1/3 relief innings, before finishing the year with a 3.05 ERA in 24 appearances (15 starts) at Triple-A Indianapolis. A former supplemental-round Draft pick of the Orioles, Olson has appeared in the big leagues in each of the last five seasons, pitching in a career-high 35 games with the Mariners in 2010.

May, 27, split last season between Kansas City and Arizona's Triple-A affiliates, hitting a combined .238 with 10 home runs in 77 games. He briefly tasted the big leagues the previous season with the Royals, hitting .189 in 39 plate appearances.

Anthony DiComo is a reporter for MLB.com. Follow him on Twitter @AnthonyDicomo. This story was not subject to the approval of Major League Baseball or its clubs.