Even with the loss of Shelby Miller the Cardinals still have a solid rotation of starting pitchers, in Adam Wainright, Michael Wacha, Lance Lynn, John Lackey and Jaime Garcia, but they cannot assume that their projected starting five will all stay healthy throughout the course of the 2015 season. Garcia has not started more than 30 games since 2011 and Michael Wacha started only 19 games last year due to shoulder problems. So, what does this mean? Well, an initial instinct of most general managers would be to check out the free agent market and see if there are any veteran pitchers available. Currently, free agents Jason Hammel and Brandon McCarthy are proven big league pitchers and would mesh well with the Cardinals staff, but although signing a free agent may seem like a good investment, I believe that the Cards already have a player on their roster who can step up to the challenge. His name is Carlos Martinez.
The 22-year-old Martinez has already spent the majority of two seasons on the Major League roster and he has the numbers to back his case. Although Martinez has been used mostly as a reliever during his time with the Cardinals, he has had a good amount of major league experience for someone his age and has only allowed 5 home runs over 117.2 innings pitched in the majors while posting a ground-ball to fly-ball ratio of 55/45%. Martinez also has a very low career FIP of 3.15. This suggests that his career ERA of 4.28 is inflated and is likely to be more in line with his FIP in the years to come. Martinez was also used exclusively as a starter during his minor league career so the switch from reliever to starter should not affect him whatsoever mentally.
What makes Martinez a valuable asset to the Cards bullpen is his live arm, his ability to strike people out and his tendency to keep the ball in the ballpark, but now that Jordan Walden and Matt Belisle are part of the pen it would be inefficient for Martinez to occupy the same role that he did last season. Regardless of a soft innings cap on Martinez next season (probably around 140-150 innings) it makes more sense for the Cardinals to use Martinez exclusively as a starter instead of as a reliever.