While he is walking fine, Harper has limited mobility because of the swelling in the knee, according to manager Matt Williams.
"[Harper] banged his left knee pretty good," said Williams. "He [came close to finishing] the game, but overnight, there was pretty significant swelling. So we will try to get that out of there today. Anytime he gets on base, [the left knee] is his sliding side. We'll give him as much time [as he needs]."
Harper said there is no guarantee that he will be back in the lineup on Wednesday. He has a suffered a bone bruise in his left knee and it didn't get any better after Tuesday's loss. The healing could take some time.
"I'm going day by day. We'll see how it feels tomorrow. If I can get back in tomorrow, I will. If not, hopefully, I'll get back in there in San Francisco [on Thursday]," Harper said.
Harper is having the best year of his career, hitting .333 with 29 home runs and 69 RBIs. Harper is looking to become the 26th player to hit at least 30 home runs in a season at 22 years old or younger. Although he has not hit for power lately, Harper is hitting .318 with a .434 on-base percentage since last homering on July 29.
"That's a consistent approach. Home runs happen. You can't force them," said Williams, who hit 378 career big league homers. "There is no reason he couldn't have another home run streak like he had earlier in the season. Home runs happen naturally. If you try to force it, then you end up not hitting at all. He has maintained his approach, he has maintained his patience. The home runs will come, too."
Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the Time. He also can be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.