Derrick Goold posted an interesting article a couple days ago stating that Carlos Martinez could be this year's Trevor Rosenthal.
If you remember, Rosenthal was slated to compete for a rotation spot in the spring, along with Joe Kelly and Shelby Miller. However, he was bumped to the bullpen without really getting a shot at the rotation, while Kelly and Miller battled it out for the final spot.
Fast forward to spring 2014 and we could find Martinez in a similar situation. After a nice showing in relief down the stretch and in the postseason, the Cardinals, who have several options for the rotation, could slot Martinez in the bullpen, basically replacing Rosenthal as setup man.
Martinez could certainly excel in that role. However, Martinez could be a whole lot more valuable as a starter, with the upside of an ace.
To me, it would make more sense in the long run if the Cardinals followed the Michael Wacha 2013 development plan. Keep Martinez in AAA to work on his secondary pitches and as insurance should injuries occur in the rotation.
After a very strong spring, the Cardinals were highly tempted to include Wacha on their opening day roster, but with the exception of a 3-start stint in late-May and early June, Wacha spent most of the year in the minors, mainly trying to refine his breaking ball. He was called up to make a spot start on August 10th, then spent the next 3 weeks in the bullpen before returning to the rotation for good on August 28th.
All told, Wacha worked 180.1 innings in 2013, including 30.2 in the playoffs, which was a 46 innings increase over his 2012 workload (Wacha pitched 134.1 innings in 2012, including college).
The Cards reportedly wanted to limit Wacha to 150 innings in 2013, which they did--in the regular season. However, his dominance in the post season proved too valuable for the team to pass on and they leaned on him heavily in the playoffs and World Series.
In contract, the Cardinals placed a 180 innings limit on fellow rookie Shelby Miller and, after pitching 173.1 innings in the regular season, the team only used him for one inning in the post season.
Due to a late start to his season and being used primarily in a relief role in the majors, Martinez logged just 120.2 innings this year. Thus, its likely the Cardinals would limit him to a similar 150 innings as they placed on Wacha and, if they follow the same development path as they did with Wacha, they can accomplish just that.
If the Cardinals put Martinez in the bullpen for all of 2014, he would be limited to around 70-80 innings for the year. Then, if the Cardinals needed him to fill a rotation spot in 2015, he would be hard pressed to throw the requisite 160-180 innings required of a full-time starter.
The ideal scenario would be to start Martinez in the bullpen as the setup man for Rosenthal to begin the 2014 season. Then, when Jason Motte proves healthy, he can take over the setup role and Martinez can return to the minors to further his development as a starter.
This would help limit Martinez' innings while also allowing him to complete his development and perhaps, down the stretch, we can see Martinez become the 2014 version of Wacha.