The Minnesota Twins have signed right-handed pitcher Rich Harden to a minor league contract and invited the free agent to major league camp for spring training, the team announced Friday, Dec. 21.

Harden, 31, missed last season after January surgery on his right rotator cuff. Harden has a 59-38 career record and 3.76 ERA in nine seasons with the Oakland Athletics, Chicago Cubs and Texas Rangers.

Meanwhile, left-handed pitcher Scott Diamond underwent arthroscopic surgery to remove a bone chip from his left elbow Tuesday, the team also announced Friday, but is expected to be ready for spring training.

Diamond could be the only holdover from a rotation that already has added candidates Vance Worley, Kevin Correia, Mike Pelfrey this offseason, as well as Harden.

Harden was 4-4 with a 5.12 in 15 starts for Oakland in 2011.

The Twins said others invited to major league camp will be:

-- Pitchers Bryan Augenstein, Nick Blackburn, Deolis Guerra, Alex Meyer, Lester Oliveros and Anthony Slama;

-- Outfielders Brandon Boggs and Clete Thomas;

-- Infielders Jeff Clement, Chris Colabello, Ray Olmedo and Mark Sobolewski;-- Catchers Kyle Knudson, Danny Lehmann and Dan Rohlfing.