The old days. (Photo by John McDonnell/The Washington Post)

What mattered to Ryan Zimmerman is that he is playing again. He doesn’t really get into anything deeper, he said. He did not pause to consider the oddity or meaning behind the Nationals’ lineup card, which listed him batting fifth and, for the first time in his 10-year career, playing left field.

“It’s a just baseball game,” Zimmerman said. “I’m just a little further out.”

After he missed 44 games with a broken right thumb, Zimmerman returned Tuesday night at Nationals Park. He will slip on a black outfielder’s glove – borrowed from Jayson Werth – over his left hand. He will hop out of the first base dugout. He will trot past third base, the position he manned his entire career, and into left field, into the rest of his career.

Over his seven weeks on the disabled list, Nationals coaches posed the idea to him. He accepted immediately. “That takes a very selfless, humble person,” center fielder Denard Span said. He practiced for three weeks and played three games at Class A Potomac. Because it allows the Nationals their best lineup, he will play in the majors Tuesday night.

“At first, just like anything, you’re a little hesitant,” Zimmerman said. “You don’t want to learn a new position. Like I’ve said, any other guy in this room would do whatever it takes to win. I think all of us realize we don’t have unlimited years to have a team like we have right now. My goal is to win, win as many games as we can, and get to the playoffs and try and do something special. This gives us the best chance.”

Zimmerman believes the throw from the outfield, because it requires less precision and allows for more time, will be easier on his surgically repaired right shoulder. Despite inexperience, Zimmerman believes he can achieve adequacy. That’s all he wants.

“I feel like I’m athletic enough to blend in and not cause any problems,” Zimmerman said.

The Nationals know there may be line drives that freeze him or throws that sail to the wrong base or sail past a cutoff man. “We’re willing to accept all of that,” Manager Matt Williams said. “His concern is getting back into the lineup.”

Williams said he did not view Zimmerman’s position switch as permanent. “I think he’s a third baseman who’s been pressed into duty,” Williams said. But in order to keep Anthony Rendon at third and Danny Espinosa at second, Williams said Zimmerman will be the Nationals’ left fielder for the “majority” of games – at least until Bryce Harper’s return, which is scheduled for early July.

When Harper comes back, Williams will face difficult decisions. Their infield defense would be greatly diminished with Zimmerman at third, Rendon at second and Espinosa on the bench. Harper could shift to center, but then the Nationals would lose Denard Span’s defense. Zimmerman could play first, but Adam LaRoche has been Washington’s most productive hitter.

“That’s too far away,” Williams said. “We have to worry about tonight. The thoughts about when Bryce comes back is that, he’ll go back into left field and Zim will come back to the infield. That’s the initial thought. But we have to see how everything goes. We just can’t say at this point.”

“When Harp comes back, Harp’s the left fielder,” Zimmerman said. “I’ve been taking groundballs at third still, and I’ve been taking groundballs at first. We haven’t really talked about what will happen the rest of the year. I’m willing to play wherever they think will give us the best chance to win.”

Though it will provide new challenges, playing left field will likely be less taxing on Zimmerman. His shoulder issues caused him to miss a game one week into the season. His wayward throws and awkward motion – both a product of years of cortisone shots, surgery and dives in the dirt – led to embarrassment.

“The last couple years at third have been tough for me, mentally, physically,” Zimmerman said. “I’ve had to really grind it out. It’s been tough. To learn something new, to go out there, sort of just go out and have fun and play ball again is refreshing, I guess, if you want to say it that way. Most importantly, what I’ve said before, it gives us the best chance to win. That’s the point.”

If Zimmerman had not been so willing to play left field, “we would have a dilemma,” Span said.  An all-star, the face of the franchise, Zimmerman could have thrown a fit or refused to play a position other than the one at which he won the 2009 Gold Glove. Instead, he dove headlong into the assignment.

“Ryan Zimmerman is about one thing, and that’s about winning and the best thing for this organization,” utility man Kevin Frandsen said. “He’ll talk to you guys and you might hear it. He’ll talk to us and you definitely hear it. It’s all about the Nationals. How can we win?”

For the Nationals to win, a quick transition will help. Now that the plan does exist in the abstract, another team will be able to impose itself on the experience. Phillies Manager Ryne Sandberg said his base runners will force Zimmerman to prove himself.

“We’ll watch a little bit,” Sandberg said. “We have no idea since there’s no pregame or anything, we don’t have the luxury of watching him. That’s something we’ll take a look at and, yes, we’ll test him.”

Span said he would chatter with Zimmerman constantly, making sure Zimmerman shifted over a few steps depending on the batter. Span knew it would be a strange experience. Zimmerman may brush aside the strangeness of switching positions. But he can’t hide it.

“You can kind of see it on his face,” Span said. “I’m not sure if he’s nervous or whatever. It’s different.”