Tommy Hanson, Jason Vargas and Joe Blanton were acquired by general manager Jerry Dipoto to take the place of the above trio. The prevailing thought is that they'll be challenged to produce at the level of the departed threesome.
While that will no doubt continue to be a topic of discussion as spring training marches on, another starter for the Angels could well hold the key to the success of the starting rotation -- C.J. Wilson.
Wilson's first year for the Angels reads like a Dr. Jekyll/Mr. Hyde-type tale.
Wilson started strong out of the gates, posting a 9-5 record and 2.43 ERA in 18 starts. Wilson was absolutely as advertised after successfully transitioning to the starting rotation from the bullpen for the Texas Rangers.
However, after the All-Star break, Wilson was a completely different pitcher. He posted a 4-5 record with a 5.54 ERA in 16 starts with a 1.571 WHIP.
Wilson's biggest issue was control; he placed fourth in the majors in walks, issuing 91 free passes for the season.
At the end of the season, the Angels announced that Wilson would undergo surgery to remove bone spurs in his left elbow.
"I tried to make a million adjustments to get around it, to the point where now I'm standing on the first-base side, trying to get an angle because I can't throw sinkers anymore because my arm doesn't work right," Wilson said. "But you're paid to go out there and play."
Wilson underwent a similar procedure back in 2008 when bone spurs forced an end to his season. He came back to post a solid 2.81 ERA in 74 relief appearances in 2009.
With the prevailing belief that the Angels' rotation this season is somewhat weaker than last year's version, it becomes incumbent upon Wilson to regain his 2012 first-half form.
Wilson is at his best when he's able to effectively use his complete arsenal of pitches. A plus-fastball combined with a curve ball, slider, cutter and changeup give him five pitches that he can use in any given situation.
Wilson was unable to fully extend his elbow for much of the second half last season, rendering his cutter and slider almost useless. In addition, he was forced to make some adjustments in the second half, limiting his overall effectiveness and command.
With a healthy elbow, Wilson has clearly shown the ability to keep hitters honest. Right-handed hitters have an especially hard time when Wilson has his slider dialed in, the ball diving in on their back right foot.
With an elbow devoid of pain, Wilson could well be a major key to the success of the Angels in 2013.
Doug Mead is a freelance sportswriter living in the Los Angeles area. His work has been featured in Bleacher Report, the Seattle Post-Intelligencer, SF Gate, CBS Sports, the Los Angeles Times and the Houston Chronicle.