The Nationals’ Ryan Zimmerman — shown here in Spring training — says he isn’t in shape. “I was out of breath for a while after that triple so you know you got to be able to do things like that, score from second and not be out of breath for half an inning.” (STEVE NESIUS/Reuters)

It was a welcome sight but in an unusual setting: Ryan Zimmerman, the Washington Nationals’ best player, batting third, just ahead of phenom prospect Bryce Harper. But instead of forming the heart of the Nationals’ lineup, Zimmerman joined the 18-year-old Harper here at Municipal Stadium, where on Sunday the third baseman began his first minor league rehab assignment with the Hagerstown Suns.

In five solid innings in a 6-5 win over the Greensboro Grasshoppers, Zimmerman quickly showed that his bat was ready for a major league return but admitted after the game that his body and throwing weren’t quite there yet. The all-star third baseman, who has missed all but the season’s first eight games with a torn abdominal muscle, went 2 for 2 with an RBI, scored two runs and made one defensive play.

But after scoring from second in the second inning and stretching a deep fly ball to center field into a triple in the fourth, Zimmerman said he was winded and that his surgically-repaired abdominal muscle was still a little “sore.”

“Hitting is usually the first thing that comes to me,” said Zimmerman, who had been rehabbing in Viera, Fla., at extended spring training. “It’s more just getting out there and getting in shape, getting into game shape and running like I did today. I was out of breath for a while after that triple so you know you got to be able to do things like that, score from second and not be out of breath for half an inning.”

The pairing of Zimmerman and Harper, however, was brief. After Zimmerman reached on a walk in his first at-bat, Harper was hit by a pitch by Greensboro pitcher Jheyson Manzueta — a play that caused Nationals principal owner Mark Lerner, who was seated behind home plate, to cringe.

The pitch hit Harper — the No. 1 overall pick of the 2010 draft who has torn through the low-A South Atlantic League with a .338 batting average and 13 home runs — in the left knee in his first at-bat of the game. Harper fell onto his back, hobbled off the field with help and left the game.

Later, Harper was seated in plain clothes during the game near the clubhouse with a wrap around his knee. He was not made available to talk to reporters after the game. Suns Manager Brian Daubach said Harper’s injury appeared to be a bruise, that no x-rays were scheduled and it would be re-evaluated Monday morning.

“It’s just a fluky thing,” Daubach said of the short-lived pairing. “It’s just baseball and what happens, and it’s unfortunate it happened today. I know [Harper] was excited to play with Zim.”

Zimmerman, who last played for the Nationals on April 9, said he wasn’t sure how long it would be before he rejoined the team and certainly did not want to rush a recovery which has already tested his patience. Although he felt better than before, he said his throwing and defense — which puts strain on his torso — still needed to be strengthened.

“Whenever I’m ready and I feel like I’m 100 percent then I’ll go,” Zimmerman said. “. . . I’m definitely going to play another minor league game. I don’t know how many but I’ll get a few more.”