Zimmerman initially was hopeful he wouldn't need to miss more than a day or two after getting hit by Santiago Casilla's pitch in the ninth inning at AT&T Park. He has participated in some drills during batting practice, but he's still experiencing pain when swinging a bat.
Multiple X-rays taken the day of the injury came back negative. Manager Dusty Baker today referred to the ailment as a "bone bruise."
"Like I told people before, when you get hit like that, ball on bone and then it doesn't heal, there's no muscle in there. You can treat it all you want," Baker said. "Anybody who's ever had a bone bruise knows it stays sore for a long time, especially in your hands, when you have to make that movement. That's what's bothering him: To make that final movement. We'll just hope that he's better in a day or so."
The Nationals have been forced to play a man down for four straight games, but for now they aren't viewing the disabled list as necessary.
"We haven't talked about it," Baker said. "Naturally, the longer you go, the more you think about it. But so far, so good."
With Zimmerman out tonight, Clint Robinson is starting at first base, batting seventh against the Giants. Daniel Murphy has also seen time at first base in Zimmerman's absence, with Trea Turner playing second base and Ben Revere in center field.
Update: We're through the third inning here at Nationals Park, and the home team has gotten this homestand off to a good start. The Nats lead 3-0 thanks to singles by Jayson Werth, Bryce Harper and Murphy in the bottom of the first (with a Wilson Ramos sacrifice fly thrown in for good measure) and then a hustle double by Turner and sac fly from Harper in the bottom of the third.
Werth extended his streak of games reaching base to 36, tied with Miami's Marcell Ozuna for longest in the majors this season. And Harper has had a couple more solid swings tonight, building off his game Wednesday at Arizona. Gio Gonzalez, meanwhile, has faced the minimum through three innings on 42 pitches. A first-inning walk of Eduardo Nunez is his lone blemish so far, but he erased that by picking Nunez off first.
Update II: Make it 4-1 Nationals after five, thanks to a pair of solo homers. Angel Pagan took a 2-2 fastball from Gonzalez deep to left in the top of the fourth, getting the Giants on the board and accounting for their only hit so far vs. Gio.
Turner responded with a shot to left in the bottom of the fifth, his second straight game with a homer. Get this: Turner is now slugging .550 in the big leagues this season. That's third-best on the Nationals, behind only Murphy (.630) and Stephen Drew (.536). That's, uh, unexpected.
Update III: Make it 5-1 Nats after seven. Ramos launched a homer to straightaway center field in the bottom of the sixth, his 17th of the season. That's a new career-high for the Buffalo. Gonzalez, meanwhile, is done after seven spectacular innings of two-hit ball.
Update IV: That's your ballgame. Sammy Solis and Mark Melancon closed this one out, securing the Nats' 5-1 victory. They've won four in a row and have improved to 21 games over .500 for the first time this season.