Twins sign Harden, Diamond has minor surgery. Non-roster invites

The Twins have reached agreement with righthander Rich Harden on a minor league contract that includes an invitation to spring training.

Harden missed all of last season while recovering from rotator cuff surgery in January. It's a very low-risk move to see if the oft-injured Harden can bounce back. Despite his injuries, Harden averaged 9.20 strikeouts per nine innings from 2003-11, thanks to top shelf stuff.

But the other news is that lefthander Scott Diamond, the Twins' most effective starter last season, was in New York on Tuesday to have a bone chip removed from his left elbow. The procedure is a simple one but still raises an eyebrow.

The Twins also announced their list of non-roster invites to spring training: : Righthanders 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; and catchers Kyle Knudson, Danny Lehmann and Dan Rohlfing.