The Chicago Cubs demoted pitchers Randy Wells and Travis Wood to the minors today, reports Paul Sullivan of the Chicago Tribune. The cuts opened the door for Chris Volstad and Jeff Samardzija, who will round out the rotation behind Ryan Dempster, Matt Garza, and Paul Maholm.

Wells, 29, has started at least 23 games for the Cubs in each of the past three seasons, posting a 4.01 ERA in 500 innings. Sending down a veteran pitcher with a decent big-league track record is surprising by itself, but the fact that Wells is also under contract for $2.7MM in 2012 makes it even more surprising. Samardzija, who takes Wells' rotation spot, has five career starts in the majors.

Wood, on the other hand, has had a rough spring and was expected to be sent down. Acquired in the trade that sent Sean Marshall to the Reds, Wood has struggled with control problems with the Cubs. The demotions of both Wells and Wood shows Chicago's new found rotation depth. The acquisitions of Volstad and Maholm in the offseason, along with the the rise of Samardzija, means the Cubs are well covered in case of injury.