Ryan Zimmerman may need a cortisone shot for his ailing right shoulder, which could land the Nationals' third baseman back on the disabled list.

Zimmerman, an all-star in 2009, has already had a stint on the DL from April 27 to May 8 for the injury, missing 13 games.

"I've been hitting for a while here and I don't miss fastballs like I've been missing fastballs," he said after going 0 for 4 in Saturday's 3-1 win over the Orioles. "It's frustrating. .?.?. If things keep going the way they have been going, we're going to have to do something."

After finishing Saturday, Zimmerman's average dropped to .218 in 55 games and his inflamed right shoulder joint, which he only recently admitted wasn't 100 percent, continued to be an issue.

Zimmerman will receive treatment on his shoulder – massages, ultrasounds – to help. But if that doesn't improve the injury, the 27-year-old may need the cortisone shot.