Ryan Zimmerman goes through some drills at Harrisburg. (Kyle Mace for The Washington Post)

HARRISBURG, Pa. — In the top of the fourth inning of Class AA Harrisburg’s loss to the Bowie Baysox Thursday night, the Baysox had a man on first with no one out. Garabez Rosa, the Baysox right fielder,  hit a grounder to first, where rehabbing Ryan Zimmerman slid right and charge, hoping for a quick snag he could spin into a double play.

He bobbled the ball — no indication of any trouble with the plantar fasciitis in his left foot, just a bad hop — so by the time he picked it up he had to hurry. Zimmerman pivoted, then charged to the first base bag with a few quick, hard steps. He beat Rosa there, salvaging an out, showing the ability to navigate the mobility-related rigors of his position with no trouble, despite the pain in his left foot that forced him to a rehab assignment in the first place.

The Nationals placed Zimmerman on the disabled list retroactive to June 10, hoping rest would alleviate some of the pain caused by plantar fasciitis, known as a chronic annoyance, not a quick-healing deal. He had dealt with the pain since late April, though mostly just on the bases until just before his disabled list stint, when he says he began to feel it in the field and at the plate. Running, then, has been the last hurdle, and after he played seven innings in his third rehab game Thursday night, Zimmerman said he feels “pretty close” to 100 percent running.

“I think the good thing is I haven’t been sore any of these days afterward, that’s kind of what was getting me before,” Zimmerman said. “I’ve been able to play and feel good the next day, and now it’s all about getting at bats and starting to feel comfortable.”

Zimmerman went 0 for 2 and reached on an error Thursday night. He struck out swinging in his first at bat, chasing a ball in the dirt. He lined to deep center in his second, then hit a hard groundball to the shortstop hole in his third, one misplayed by the shortstop. A few batters later, he ran first to third — not running freely, but running well enough to get where he was supposed to without holding his team back.

“Felt pretty good [going first to third],” Zimmerman said. “I wasn’t going crazy or anything, but felt good enough to be productive and not feel like I have to go station to station.”

That is the goal, Zimmerman said last week: not to completely eradicate the pain, but to manage it enough that he does not feel it at the plate or in the field, and can run through it well enough that his team does not have to worry about him on the bases. He also needs to get at-bats, as he has been out for more than a month and will admit he wasn’t hitting very well before the disabled list stint, either. Instead of swinging early, jumping on the first good pitch, Zimmerman said he is taking his time at the plate in these rehab at bats — seeing as many pitches as possible, trying to sync his timing, watching as many breaking balls as he can.

Zimmerman said he does not have a timetable for a return, though he will need to play nine innings at least once — and probably more than once — before returning to the Nationals. Zimmerman is scheduled to stay with Harrisburg over the next couple days, and did not know whether he would be the designated hitter Friday or play the field, though he expects to play somewhere and continue his progress toward a return.

“First of all I have to go up there and play every day. It’s not worth it to go up there and play two days and need two days off. That kind of puts them in a bind,” Zimmerman said. “When I’m ready to go every day, that’s kind of what we’re waiting on. As far as the at bats, who knows. It could be 15-20 at bats, it could be 25. I’m obviously not gonna stay down forever. At some point, you just have to go with what you got.”

Left fielder Jayson Werth got a day off during his rehab assignment with Class AAA Syracuse Thursday, and is expected to be back in the Chiefs’ lineup Friday. Anthony Rendon batted second and played third for nine innings with Class A Potomac Thursday.