"Third baseman Ryan Zimmerman is unsure about the severity of his strained abdominal muscle and when he may return after aggravating it Saturday night sliding headfirst into second base. Asked how worried he was, Zimmerman responded only by saying, "Don't know."

Zimmerman first strained his abdomen a week into spring training games, but at the time he called that ailment "a non-factor." Zimmerman had started feeling the muscle right in the middle of his stomach flare up once the season began, but it severely worsened Saturday night.

"It felt bad enough not to play today," Zimmerman said. "It's worse than it was. It's not terrible. So we'll see. It kind of goes in and out. Every one in here has their own bumps and bruises. I just hope it doesn't get worse."

The Nationals will re-evaluate Zimmerman on Tuesday after an off day. They have not yet considering sending Zimmerman to the disabled list, but his vagueness certainly seems like a bad sign."