Mattheus day-to-day with inflammation in his chest

VIERA, Fla. - An MRI taken yesterday afternoon has revealed that Nationals reliever Ryan Mattheus has costochondritis, which is inflammation of the cartilage that attaches the ribs to the breastbone. Doctors have told Mattheus he's day-to-day at this point. Mattheus first started feeling pain in his upper chest after throwing his second bullpen session of spring, back on Feb. 18. He was shut down for a few days, but when the pain didn't dissipate, the Nationals sent Mattheus for an MRI in order to try to determine the cause of the discomfort. Costochondritis is typically caused by forceful coughing, which leads to inflammation in the chest. Mattheus is a seemingly rare case of an athlete coming down with the condition despite a lack of illness or physical collision. "I think it's gonna be one of those things, whatever I can tolerate without aggravating it worse and setting us back," Mattheus said. "So I think it's good news. Nothing's broken, no muscular tears or anything like that. It's just a tough spot because there's no blood supply there, and the blood gets in there and heals stuff. So there's not much circulation there. Sometimes it takes a while for the pain to get out of there. "I'm just waiting now to see if I can do something, maybe light throwing, with no pain. Just little activities so that it doesn't keep me out completely." Nationals medical director Dr. Wiemi Douoguih is going over Mattheus' test results and will determine the best course of action going forward. Mattheus would like to stay active in some regard, whether it's riding a bike or doing some light tossing, just so that his recovery time is shortened. Typically, for every week a pitcher sits out due to an injury, the Nats like to have them rehab a week once they're ready to work back toward game action. Mattheus says that the pain has slowly started to dissipate in recent days, but it still hurts when he breathes heavily, laughs or coughs. "The frustrating thing is it doesn't hurt with any activity," Mattheus said. "I threw the day after and I was fine. I got through that. I did PFP (pitchers' fielding practice) and all that. It's just the jarring from hitting the ground, heavy breathing from conditioning or something like that. Laughing, someone makes me laugh, that's more of the stuff that bothers me. Not more of the baseball activities. But we'll figure it out." Mattheus is battling for a spot in the Nationals bullpen this spring, and he comes into the year looking to put a disappointing 2013 behind him. After putting together a strong 2012 and serving as a key member of the Nats' relief corps, Mattheus posted a 6.37 ERA in 37 games last year. He would like to get to the point that he can return to bullpen sessions and workouts with his teammates in order to try to win a spot on the opening day roster, but that's been put on hold for now.