Competition for the back end of the Pirates’ season-opening rotation has just gone from a match race to an all-out scramble.

Jeff Karstens was scratched four hours before he was to make his first Grapefruit League start, due to “continuing discomfort” in his right shoulder. Additional details will come from GM Neal Huntington later this morning, but the development at the very least ensures that Karstens will begin the season on the DL, not on a mound.

So, suddenly, there are two open spots in Clint Hurdle’s rotation. Instead of battling for one spot, Jeff Locke, Kyle McPherson, Chris Leroux, Jonathan Sanchez and even Jeanmar Gomez are now competing for two.

Leroux will step in to make the start today against the Orioles. Sanchez, interestingly, can ask for his release today if not placed on the Major League roster. Sanchez and Gomez have both  been extremely sharp in their last two outings, and Gomez has the advantage of already being on the roster.

More to come.