Harper did not speak with the media before or after Tuesday's 7-5 win over Myrtle Beach, but tweeted late Tuesday night that he "had a great time," and "felt great." If nothing changes, he is expected to play about six more innings on Wednesday.
Before the Nationals' 7-5 win over the D-backs on Tuesday night, manager Davey Johnson said he hopes his All-Star left fielder will return to the team next Monday, when the Brewers open a series in Washington. Harper could play with Potomac for two more games as the club finishes its homestand, then continue his rehab at low Class A Hagerstown, where his older brother Bryan is a relief pitcher.
"Harper will take four, five, six days maybe to get [ready]," Johnson said. "Hopefully, he doesn't have any problems playing on [the knee]. That's the big thing. I'm not so much worried about his timing. It's how he reacts after he plays on it.
"He will probably do three or four innings [Tuesday] and gradually, if there is no problem, up it. ... He goes 150 percent, even if it's just three innings, he is not going to be babying it. He doesn't know how to do that. I'm hopeful the knee doesn't react from playing. Hopefully, he will be back against Milwaukee."
The atmosphere was electric at Potomac, where Harper never played on his quick rise through the Nationals' system. Pfitzner Stadium was packed with 8,495 fans, many of whom wore Harper's No. 34 jersey and aimed their cameras at home plate before every pitch he saw. About a half-hour before the game, when Harper hit some soft toss in an outdoor batting cage under the bleachers down the first-base line, a crowd gathered as if waiting backstage for a rock star.
"Anytime you get a rehab guy, but especially Harp, you get a lot of buzz in the crowd," said Potomac manager Brian Daubach, who also managed Harper at Hagerstown, his first pro stop in 2011. "On a Tuesday night, it can get slow around here, but it wasn't the normal Tuesday night for us."
Harper, who at age 20 is still younger than all of his temporary teammates, gave the fans some excitement, even without hitting the ball much past the infield.
In the first inning, he dug in against right-hander Alec Asher, the starter for Myrtle Beach, a Rangers affiliate. On a 1-0 pitch, he lifted a flare into shallow left field and hustled out of the box. Shortstop Edwin Garcia raced back and got his glove on the ball, but couldn't haul it in. Harper, never hesitating, raced into second without a play and was awarded a double.
"He was flying, as good as I've seen him run," Daubach said.
But he didn't stay there for long, as Asher picked off Harper with a good throw back to second.
Harper had expressed concern recently about finding his timing at the plate, but Daubach was impressed with his second plate appearance, when he drew a seven-pitch walk off Asher in the third.
"That kid has some pretty good stuff and he pitched him really tough," Daubach said. "He laid off some sliders in the dirt, and then a 3-2 changeup, he really didn't even think about swinging at it. That was good to see this early. I know he's been out a while, and as you see with most rehab guys, the more at-bats they get, they get it back. But to have his second at-bat be a good at-bat and lay off some good pitches was a good sign."
Harper's second appearance on the basepaths went smoothly. He moved to third on Jason Martinson's double, his helmet flying off just as it did in his Major League debut at Dodger Stadium last season. He then scored on a single by Adrian Nieto.
Harper exited before the top of the fourth, after having only one ball hit toward him in left field. Myrtle Beach's Rougned Odor sliced a deep fly ball down the left-field line, and Harper gave chase, but had no play as the ball bounced over the wall for a ground-rule double.
Daubach said Harper simply didn't see the ball well off the bat in the twilight, but that he was getting good reads on fly balls during batting practice.