Washington Nationals outfielder Bryce Harper played his first minor league rehab game Tuesday night for Class-A Potomac, going 1 for 1 with a double, a walk and a run scored.Last year's National League Rookie of the Year batted second and played three innings in left field before being pulled.Harper hadn't played since May 26 and was put on the disabled list June 2 with bursitis in his left knee. He has missed 25 straight games and 31 of the first 75 this season for Washington."He looks the same old Harp," said Potomac manager Brian Daubach, who also had Harper at Hagerstown in 2011.After having the best record in the majors last season at 98-64, the Nationals have struggled without Harper and are 38-38.Harper wore a knee brace during warmups, but it wasn't visible during the game.In Harper's first at-bat he hit a popup into shallow left field that was dropped by Myrtle Beach shortstop Edwin Garcia. Harper showed no signs of the knee ailment as he raced around first base and into second for a stand-up double."The double he hit was a blooper down the left-field line and he was flying," Daubach said. "It's as good as I've seen him run."Moments later Harper was picked off by Pelicans pitcher Blake Schwartz after taking a large lead and failing to slide back in time to beat the throw."He's aggressive," Daubach said. "When he got to second, looking to take third in a situation with one out, all positive for me."In the third inning, Harper got a late start on Rougned Odor's shot into left field. He recovered to make up ground but the ball bounced over the wall for a ground-rule double.Harper's second at-bat ended after seven pitches with a walk."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," Daubach said. "But to have the second at-bat be a long at-bat and to lay off some good pitches was a good sign."The next batter, Jason Martinson, doubled Harper to third. Again Harper's knee looked fine as he raced around the bases so fast that his helmet couldn't keep up and flew off his head before he reached third.Harper wasn't at third base long as the next hitter, Adrian Nieto, singled him home. Harper, still the youngest player on the team, picked up Nieto's bat before crouching down and cheering as Martinson slid home to even the score 3-all.Potomac defeated Myrtle Beach 7-5.Although acknowledging he doesn't have the final say, Daubach answered that Harper playing six innings on Wednesday "sounds about right.""After playing for the first time in a while, hopefully he comes back ready to go tomorrow," Daubach said.Harper's appearance with Potomac created quite a buzz - and long lines outside the stadium as early as two hours before the first pitch. His batting practice session also caused quite a scene as more than 100 fans crowded around the cage, while others looked on from the top row of the first-base stands. Many in attendance wore Harper's jersey, while others took pictures trying to get a glimpse of the big league All-Star.Kids chanted his name from atop their father's necks and teenage girls gave him the rock star treatment by screaming as he was led by police officers back to the dugout after the session.It was the first sellout of the season for the Potomac Nationals."On a Tuesday night it can get slow around here," Daubach said. "It wasn't the normal Tuesday night for us for sure."Manager Davey Johnson, speaking before Washington's game against Arizona, said Harper likely won't rejoin the Nationals this weekend when they travel to New York."I doubt if he'll be able to make it that quick," Johnson said, pointing to a series starting next Monday in Washington against Milwaukee for Harper's likely return. "He'll probably do three or four innings tonight, and then, if there's no problem, gradually up it."Outfielder Jayson Werth, who left Sunday's game with a strained left groin, was in the Nationals' starting lineup against Arizona.The Nationals also placed pitcher Dan Haren on the 15-day disabled list, retroactive to Sunday, with right shoulder inflammation. They also recalled first baseman-outfielder Tyler Moore from Triple-A Syracuse.Haren underwent an MRI exam Monday, which he said revealed no structural damage, and he received a cortisone shot."There's nothing surprising definitely," Haren said. "Obviously, there was a little bit of inflammation and stuff in there. I don't know if that's normal wear and tear, or maybe a little bit more than normal. I got a shot, which is the best way to take out all the stiffness and any inflammation that's in there."The 32-year-old right-hander said he could begin throwing again as early as Wednesday. Signed to one-year, $13 million contract in the offseason, Haren is 4-9 with a 6.15 ERA in 15 starts. On Saturday, he lasted just 3 1-3 innings, allowing six runs on seven hits in a 7-1 loss to Colorado.Moore is batting .158 with five doubles, two home runs, 13 RBIs and seven runs scored in 38 games this season with the Nationals.