"Maybe he can do the Kirk Gibson," Baker said before the game. "But other than that, we're going to try stay away from him, and then we'll make an evaluation [Wednesday]."
Harper tried to run the bases after getting hit by a pitch in the seventh inning on Monday, but was eventually doubled off first base on a line drive to left field. He was removed from the game before the bottom of the seventh.
"It just feels the same as yesterday," Harper said. "There's nothing good or bad or anything."
Harper is batting .242/.415/.535 with 13 home runs in 51 games this season. On Tuesday night, Jayson Werth filled in for Harper in right field, while Clint Robinson got the start in left field.
Neither Harper nor Nationals have sounded overly concerned about the extent of Harper's injury, although Baker mentioned the team's off-day on Thursday, meaning they would not be likely to rush him back on Wednesday if he does not improve dramatically. Harper showed up early to the ballpark before Tuesday's game for treatment and said he will try to keep his knee as active as possible.
"Keep it bent, keep it going," Harper said. "Hopefully it won't stiffen up too much. ... I'm just trying to keep it moving, keep it going and see where we're at [Wednesday]."
Jamal Collier covers the Nationals for MLB.com. Follow him on Twitter at @jamalcollier. This story was not subject to the approval of Major League Baseball or its clubs.