The Cubs have signed Jon Lieber, reports the Chicago Sun-Times. MLB.com (no article yet) reports the deal is worth $3.5M. The S-T speculates that "the move could pave the way for the Cubs to trade young pitchers to Baltimore for Brian Roberts." Ken Rosenthal speculates that this "could signal a trade of right-hander Jason Marquis or the return of righty Ryan Dempster to the bullpen." (Hat tip: Wrigleyville23.)

I appreciate Lieber's service to the Cubs from 1999-2002 as much as anyone. But why this now? Lieber will be 38 in April. Over the past two seasons for the Philadelphia Phillies, Lieber has thrown 246 innings with a 4.87 ERA.

Guaranteeing Lieber's contract almost certainly means that Sean Marshall (who was 34th in adjusted ERA out of 127 starting pitchers with at least 100 innings pitched last year) is out of the rotation and perhaps gone from the team in a trade for Roberts, unless the Cubs find someone to take Marquis' contract and move Dempster back to the bullpen (which likely means putting him back in the closer role). Oh, and Sean Gallagher and Kevin Hart do not get chances to compete for the starting rotation.