J Pat Carter/AP

Jayson Werth played his fourth straight game in Class A Potomac on Saturday, further testing his improving hamstring and remained on track to rejoin the Nationals on Tuesday. Werth played only five innings, a shortened performance so that he could play close to nine innings on Sunday, which he expects to be the final game of his rehab stint before coming off the disabled list.

Werth went 2 for 3 with a run scored and played right field for five innings. His movement on the field ranged from, mostly, light jogging to running. He jogged to first on his first single and ran harder on his second hit, a bloop single that dropped into right field. He scored from second on a single in the third inning, running hard and sliding into home plate. He jogged lightly out of the batter’s box in his fifth inning pop out. Afterward, Werth admitted there was still one minor and remaining step of running to test.

“I’ve progressed each day,” Werth said of the hamstring. “I feel better and better and I think we’re at a point. I scored from second on a base hit and I’ve been moving around and playing the outfield. That last 10 percent is really what I was looking for and I think I’m at a spot where I can be confident and play my game without worrying about getting injured.”

Werth, who last played on May 2, already had a shortened rehab stint on May 15 when he played three innings for Potomac. He felt his hamstring tighten again as he raced out of the batter’s box in his first at-bat. A subsequent MRI revealed that he had a more significant hamstring strain that originally thought. Werth has been resting his hamstring and receiving treatment, slowly ramping up his workouts last week.

With his second rehab stint in Potomac, which started on Wednesday, Werth took a cautious approach. He played at 60 percent effort in the first game and slowly increased his speed and innings played. Running home from third in the first inning and scoring in the third inning were perhaps the hardest runs by Werth in his second rehab stint here. His injury confounded the Nationals and Werth initially because he was dealing with cramping and dehydration at the time.

“These hamstrings are tough,” he said. “I’ve never had one before and I’m kinda going through this for the first time. The last time I came out here I had two weeks and I felt really good. And then I went out and played like I’ve always played and it was just too much. I wasn’t ready for that and you don’t really know that until you go 100 percent and find out you’re not ready. That was the plan, to ease into it, and step by step and gradually get back to close to full speed.”

One matter to clear up confusion: Manager Davey Johnson had said Werth was expected to play a full nine innings on Saturday so when Werth exited the game after five innings there was a momentary concern that perhaps he had aggravated his hamstring again. But it appears there was a miscommunication. Sunday is a day game, and not a night game as originally thought, so Werth played an abbreviated game on Saturday so he could rest and return for a full game Sunday.

Werth’s return to the Nationals could help stabilize an injury-depleted Nationals roster. Wilson Ramos, Bryce Harper, Ryan Mattheus and Ross Detwiler are also on the disabled list. Stephen Strasburg’s status is up in the air. Harper landed on the disabled list on Saturday with lingering left knee bursitis.