Ryan Zimmerman is hoping for no pain once he starts running again. (Nick Wass/AP)

SAN DIEGO — Ryan Zimmerman is relieved to be back traveling with the Washington Nationals, who are beginning to steady their season without his help.

That’s the part — his ongoing absence — that is most weighing on Zimmerman as he continues to recover from plantar fasciitis in his right foot. He initially went to the 10-day injured list on April 28 after nagging pain in his heel started affecting his swing mechanics. He worked up to on-field running two weeks, before the team’s most recent road trip, and that pain returned. So the 34-year-old first baseman scaled it back, returning to the ultra-gravity treadmill and regressing to where he was in the middle of May.

The stops and starts of an injury rehab is something Zimmerman has grown used to throughout his career. But this one is bothering him in a different way.

“It’s been really frustrating. It’s been probably one of the more frustrating things I’ve gone through,” Zimmerman said Friday before the Nationals’ matchup with the San Diego Padres at Petco Park. “Just because the rest of my body feels so good. I felt good this year up until the point where the heel started acting up. And there’s nothing you can really do to prevent something like this.”

The step, again, is for Zimmerman to run on the field and feel comfortable doing it. He is back to baseball activities and was crushing home runs Friday during batting practice. He could see himself running after Washington returns from this trip — which includes three more games here, then two in Chicago against the White Sox — and, if that goes well, making a few rehab appearances in the minors. Zimmerman missed a 10-game road swing through Philadelphia, Milwaukee and Los Angeles in early May and another one through Atlanta and Cincinnati later in the month.

Being away from the team — and feeling even further from the action — is one of his least favorite parts of being hurt. But the worst, by far, is simply that he cannot play.

“Things like this pop up. If you go ask anybody in this locker room if something hurts, they’re all going to say yes,” Zimmerman said. “It’s just what we do. It just got to the point where if it starts affecting other things. For me, it was on my back leg, so hitting was starting to become … I was starting to do things that I don’t normally do.”

Before the injury, Zimmerman was hitting .213 with three home runs in 86 plate appearances. He is typically a slow starter, and this spring he constantly stressed the importance of staying on the field. He played in just 85 games last season, and that has only made this slow recovery more irritating. Had he felt the pain in August or September, Zimmerman says he would have pushed through it to the end of the season. But he didn’t want to do that for five or so months, which led him to the IL and into a program with the Nationals’ athletic trainers and strength staff.

Howie Kendrick and Matt Adams have mostly filled his spot, and both are playing well in split time. Kendrick has been one of the team’s best hitters with a .320 average, 10 home runs and a .941 on-base-plus-slugging percentage. Adams is a left-handed power threat who is beginning to heat up. But a healthy Zimmerman just makes Washington that much deeper, whether he is playing every day, platooning or providing a sound right-handed bat in whatever way Manager Dave Martinez needs.

The next and final step is running, maybe as soon as this coming week. Zimmerman again will hope for no pain.

“It’s feeling a lot better now,” he said. “I think it definitely feels better than it did the time before.”

LINEUPS

Nationals (28-34)

Trea Turner, SS

Adam Eaton, RF

Anthony Rendon, 3B

Juan Soto, LF

Howie Kendrick, 1B

Brian Dozier, 2B

Victor Robles, CF

Yan Gomes, C

Erick Fedde, P

Padres (32-31)

Fernando Tatis, Jr., SS

Wil Myers, CF

Manny Machado, 3B

Eric Hosmer, 1B

Franmil Reyes, RF

Josh Naylor, LF

Austin Hedges, C

Nick Margevicius, P

Greg Garcia, 2B

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