Well, this isn't good news: Shaun Marcum, who's dealt with arm injuries in the past, is in New York City because his shoulder isn't feeling quite right.

Shaun Marcum went to NYC yesterday & was given a cortisone shot for "impingement" in right shoulder. Not gonna pitch for few days. #Mets

— Jorge Castillo (@jorgeccastillo) March 20, 2013

Not pitching for a few days is definitely the best-case scenario here. The Mets' starting rotation is dependent on Marcum staying relatively healthy, and the timing here is not at all ideal with Johan Santana not yet pitching in spring training games.

What can Shaun Marcum do for the Mets?

Assuming his arm remains attached, that is.

Marcum missed all of the 2009 season following Tommy John surgery, but since then, he's averaged just over twenty-eight starts per season. Last year, he made twenty-one starts and dealt with inflammation in his right elbow. When healthy, though, Marcum has been effective, pitching to a 3.62 ERA over the last three seasons with good strikeout and walk rates.

With the injury, Marcum joins Santana, of course, as well as David Wright and Daniel Murphy on the list of Mets regulars whose status for Opening Day is at the very least in question.