Cardinals stretching out Trevor Rosenthal for role as starter

In a somewhat strange turn of events, the Cardinals will seek to use Trevor Rosenthal as a starter for the upcoming season. On Wednesday, manager Mike Matheny let his closer know that he would be stretched out in order to earn a rotation spot according to Derrick Goold of the St. Louis Post-Dispatch.

The Cardinals rotation is already somewhat crowded, but may have lost a potential member in Tyler Lyons who could be out 5-6 months after undergoing offseason knee surgery.

With one potential starter out for Opening Day, the addition of another option seems like a good thing to add to the agenda. However, the Cardinals have plenty of options at starter already, and stretching out Rosenthal is far from a sure-thing.

Rosenthal hasn’t started a game since his days with Triple-A Memphis in 2012, and he has never started at the major league level. Even further, the most innings Rosenthal has ever thrown in a season was 120.1 back in 2011 when he made 22 starts for Single-A Quad Cities. Asking Rosenthal to throw more than just 130 innings in a season is completely uncharted territory, let alone the possibility of asking for 190 innings or more that Adam Wainwright and Carlos Martinez logged in 2016.

Over the past four seasons, Rosenthal has averaged just 63.2 innings per year. As a starter, he would likely be asked to throw more than twice that even if the Cardinals worked at limiting his innings.

Compounding matters even more, Rosenthal is finishing up a season in which he dealt with a flexor strain in his right shoulder that kept him out of action for nearly two months. Known for his high velocity fastball, Rosenthal’s workload might be best when limited to short relief. Though, Cardinals’ GM John Mozeliak may be hinting that Rosenthal could be used in slightly longer relief instead:

"In terms of role we’re going to see how things go, but we’re open to anything. [Starting] was something that [Rosenthal] has had a desire to do. As we were looking at all the different moving pieces it doesn’t hurt to have an extra arm, and in the past we’ve felt like an extra arm would help. As you start to think about bullpen structure and multiple innings it makes sense to have people prepared to do more than just a one-inning stint."

A move like that, following Andrew Miller’s use in the postseason for the Cleveland Professional Baseball Team, would make more sense. Especially considering the fact that Wainwright and Martinez also already have Mike Leake, Jaime Garcia, Michael Wacha, Alex Reyes, and the recovering Lance Lynn as potential rotation mates.

If Rosenthal is going to be deployed as the Cardinals’ Miller next season, it may take some re-alignment of Matheny’s beliefs. Matheny, who just signed a three-year extension that will carry him through the 2020 season, is known for managing for the save—a statistic that sometimes overlooks using your most effective reliever in the highest leverage moment of the ball game.

While Rosenthal’s conversion seems unlikely, a case of this happening successfully recently is C.J. Wilson. Wilson was a reliever for four consecutive seasons with the Rangers before converting into a very successful starter for the next four seasons, while throwing 842 total innings. Since then however, Wilson has battled some injuries and ineffectiveness while not pitching at all in the 2016 season.

In all likelihood, all of the Cardinals’ starting options are already internal, and this news precludes them from appearing in rumors looking for external options. Instead, the Cardinals may explore other avenues of need such as the outfield.