Which pitcher will replace the injured Joe Kelly in the St. Louis Cardinals rotation?

The St. Louis Cardinals placed righthanded starter Joe Kelly on the disabled list this afternoon. The team promoted Jorge Rondon and Eric Fornataro to the majors and demoted Keith Butler in order to bolster a bullpen that was strained by a large innings load after Kelly's early exit due to a hamstring injury on Wednesday in Milwaukee. But the club still faces the decision of who will replace Kelly in the rotation.

Injuries are the worst part of any sport. In baseball, pitcher injuries are particularly awful. Whenever a pitcher signals for a trainer, ill feelings flood my gut. The kneejerk reaction is to fear for the pitcher’s season and maybe even career. I hate injuries.

That being said, if you had to choose in a macabre parlor game an injury for a pitcher to suffer, you’d probably choose the leg. And if you had to choose a part of the leg’s anatomy to be damaged, musculature would likely be the choice. The degree of injury? I’d choose a strain of the low-grade variety. And that’s apparently what Joe Kelly suffered in Milwaukee on Wednesday afternoon—a hamstring strain.

This is not to poo-poo the unfortunate turn of events. Kelly’s hamstring injury is such that the club feels compelled to send him back to St. Louis for some diagnostic imaging, which is the prudent and proper course of action. The odds are that Kelly will miss one start and probably more. After all, the typical treatment for a muscle strain is rest. Given the current state of the Cardinals’ pitching staff—especially the relief corps—I don’t think the length of Kelly’s absence will have much impact on who replaces Kelly.

When Kelly was escorted off the field, many fans called out: “Carlos Martinez!” The heart wants what the heart wants. I suspect that yours, like mine, wants Martinez in the starting rotation now and forever. Even though Martinez is hands down the best pitcher who might fill the void left by Kelly in the rotation, such a shift seems highly unlikely at the moment.

The early season St. Louis bullpen has painted for fans the picture Matheny saw during spring training. Without Jason Motte, the Cards don’t have many trustworthy righthanders. This was the driving force behind manager Mike Matheny’s decision to start Kelly and install the electric Martinez in the pen. Matheny’s heavy usage of Martinez in the season’s opening weeks bolsters this notion, and I suspect the goings-on after Kelly left Wednesday’s game against the Brewers did little to ignite Matheny’s trust in either Seth Maness or Butler when the game is late and close (or even not so late and not so close). To move Martinez to the rotation now would create a hole in an already cracked bullpen that would be filled by whom? Rondon? If the Cards moved Martinez to the rotation, who would become the righty bridge between the starting pitcher and Trevor Rosenthal in the ninth? If thinking about the answer to that question is causing a sinking feeling in your stomach, multiply that by fifty and you probably have an inkling of the level of consternation it gives Matheny. With Motte still weeks away from returning to the St. Louis bullpen, it appears extremely unlikely that Matheny would give up his favorite late-inning relief crutch.

I’m Looney for Tim Cooney. The lefty has a sparkling 2.04 ERA so far for Memphis that’s paired with an impressive 3.03 FIP, which is fueled by 17 strikeouts and five walks. If you were fantasizing about an ideal start to Cooney’s 2014, this is it. But Cooney is nonetheless unlikely to get the call to replace Kelly in the St. Louis rotation. Cooney is not currently on the 40-man roster. And while the Cards have an open slot on it that they could fill with him, Cooney is behind Lyons on the developmental curve a bit and not so much better to justify such a move. I’m Looney for Cooney; I’m not crazy. Cooney’s time is nigh, but not right now.

Tyler Lyons is the most likely choice to replace a disabled Kelly. Lyons started for Triple-A Memphis on Wednesday, the same day as Kelly’s aborted start in Milwaukee, is currently on the 40-man roster, and has the longest track record of minor-league success as a starter. While it’s true that Lyons is the least sexy potential starter currently jockeying for big-league innings, it’s difficult to argue with the results of the lefthander’s locate-four-pitches approach. Lyons’s 3.32 ERA is higher than Cooney’s, but the senior Memphis southpaw has posted a 2.78 FIP on the back of an 18 to 5 K:BB ration that is a bit better than that of his fellow port-sider. As fourstick noted in our Writers Roundtable on the fifth-starter competition, if you put Lyons’s numbers up against Kelly’s in a blind taste test, a lot of folks would probably select Lyons over Kelly. What’s more, Lyons has shouldered an innings load not much different from Kelly’s over the past two seasons. Put otherwise—going from Kelly to Lyons is not as dramatic as the falloff that so many clubs experience when going from a big-league starter to a minor-league replacement. The Cards’ pitching depth has effectively redefined “replacement level” for St. Louis starting pitchers to something higher than what is for MLB as a whole. At present, Lyons is the embodiment of that redefinition.

You hate to see a player suffer an injury, but Kelly’s could’ve been worse. Further softening the blow of losing Kelly is that the gap between the Cardinals’ No. 5 starter and their sixth starter is not very wide at all. It could be a heck of a lot worse.

Editor's Note: This post has been updated to reflect the roster moves the Cardinals announced today.