"I've been feeling a lot more comfortable start-to-start," he said. "It makes me feel good. It gives me more confidence. I feel like I'm getting stronger."

Martin allowed two runs over 6 2/3 innings against the Florida Marlins to continue his recent upswing. The 26-year-old has allowed three earned runs or fewer in six of his past seven outings and has lowered his ERA to a respectable 4.35.

Martin's results Sunday were among his best to date, but physically he admittedly wasn't in top form. He struggled early to find velocity on his pitches but managed to avoid trouble and got stronger as the game went on.

"Early on, I was a little concerned," interim manager Jim Riggleman said. "His velocity was quite a bit down. But he was hitting his spots, made some nice pitches. ... I thought he picked up his velocity as the game went on and just really did a heck of a job."

Injury updates

Craig Stammen had surgery Sunday morning to remove bone chips from his right elbow. The procedure, performed by team orthopedist Wiemi Douoguih at Washington Hospital Center, went smoothly and did not reveal any further damage to the rookie's elbow.

Stammen will need six weeks to recover and thus won't return this season, but the Nationals expect him to be 100 percent healthy well in advance of spring training.

Meanwhile, outfielder Austin Kearns is running out of time to return from a bruised thumb before season's end. Kearns, who has been out since Aug. 4, is not yet able to swing a bat. Unless he shows surprising progress in the next week, his Nationals career likely is over. (The club is expected to take a $1 million buyout on his contract rather than picking up his $10 million option for 2010.)

"It's always disappointing, no matter when, to be on the DL," Kearns said. "The DL stinks. It's no fun watching. But there's really nothing you can do about it. It's just part of it."