WOODBRIDGE, Va. -- Bryce Harper didn't see many pitches to hit Tuesday night at Pfitzner Stadium in his second rehab start for Class A Advanced Potomac since tearing his left thumb ligament in April.

But when Salem Red Sox right-hander Kyle Kraus delivered a hanging slider to Harper on a 3-1 count in his fourth and final at-bat of the contest in the fifth inning, the slugger turned his hips and drilled a line-drive three-run home run that sailed well into the trees over the right-center-field fence.

"That felt really good," Harper said. "Got into a good hitting count and put some good wood on the ball and let it go a little bit."

Harper finished the night 2-for-3 with a single and a walk to go along with the first home run of his rehab stint. He started in center field, batted second and played five innings -- two more than he did in his first game back on Monday.

Salem starter Pat Light wanted no part of Harper in his first at-bat, and the outfielder walked on four pitches before scoring on an RBI single from third baseman Oscar Tejeda.

Light continued to struggle over his 2 1/3 innings, which provided Harper with a number of at-bats early in the game, including the second and third innings. But his second time up, Harper grounded out on a dribbler down the first-base line after swinging at the first pitch despite stating Monday that his goal was to see a lot of pitches and go deep into counts.

Harper said he was sitting on a first-pitch fastball because Light had let up a walk and a single to the two previous two batters.

"I thought he would come right at me," Harper said. "But I got a little antsy and calmed myself down the [last] two ABs and felt good."

Harper showed much better plate discipline when he came up in the third inning. After taking two balls, the outfielder ripped an RBI single past the outstretched glove of leaping shortstop Mike Miller.

Catcher Wilson Ramos -- who went 2-for-5 and caught nine innings in his final rehab start before joining the Nationals Wednesday in Chicago -- followed Harper's single with a groundout to Miller. The shortstop flipped to second for the final out of the inning, and Harper slid into the base with no issues.

"I did that on purpose just to get a little drag on it," Harper said. "So that felt fine."

Typically a left fielder in the Major Leagues, Harper started in center field Tuesday night because the Nationals will need him to play all three outfield positions when he returns to the team in about a week. He didn't have a chance at a play over five innings, and the only ball that came his way was a groundball that trickled through the infield for a single.

"It's a lot of fun to play out there," Harper said. "I love it. It's the best position to play in the outfield, I think. And I enjoy doing it. I stay in the game a lot more and it's a fun place to play, and I think I'm a lot better at the plate when I play center field."

On Monday, Harper smacked an opposite-field single in his first at-bat, and after his night was done, he mentioned that the vibrations from the bat on that hit aggravated his thumb. On Tuesday, though, Harper said he experienced no pain after either of his hits, largely because he squared them up so well.

Harper will take a day off on Wednesday to reevaluate the progress of his thumb, which he said felt great Tuesday night. Harper said he'll take some batting practice and lift weights but won't see any game action.

Harper still doesn't know where he will be playing on Thursday, and he said he'd find that information out when he touches base with the team following his workout on Wednesday. Potomac plays a three-game series on the road before returning home on Saturday while Double-A Harrisburg is away until Monday. Class A Hagerstown is home from Wednesday until Monday.

As far as the length of his rehab stint, Harper is still set on playing his predetermined amount of around seven games, stretching into next week.

"I really want to stick to that same schedule -- nothing more, nothing less," Harper said. "Really just try and see where my thumb's at. If I need more, then I'm going to take more. If I feel like I can play with less, I'm going to rethink that and play as many as I can to see where my thumb goes. I haven't gotten jammed yet or anything like that. If it happens, I want to see how it feels. Hopefully it doesn't happen, because that wouldn't be good. But I really just want to see how it feels."