(Photo by Al Bello/Getty Images)

In every way, Ryan Zimmerman’s throwing is complicated. It is a subject of vital importance to the Nationals that, years into the struggle, cannot be described in simple declarations. How does his form look? How does his arm feel? How long can he play third base? The answers are not black-and-white, and they could change based on any number of factors, including the weather.

Start at the end of last year. Zimmerman made several spectacular plays and committed no errors in the season’s final 21 games. He seemed to conquer the throwing woes, which stemmed from November 2012 shoulder surgery, that threatened to consume him early in the season. Given the damage done inside Zimmerman’s shoulder, though, he did not simply pick up where he left off.

“It’s definitely re-learning,” Zimmerman said. “It’s complicated. It’s hard to explain to people that have never played baseball. The best way is to explain it is, some days are really good, and some days are really bad. It is what it is. I work hard to try to get it the best I can.”

Early in the season, cold weather has been a factor. Zimmerman does not want to admit it, because it sounds like an excuse. But Nationals coaches have observed him during games constantly loosening up his shoulder. He has not needed to this year, but in the past he has sometimes sneaked to the clubhouse between innings and placed a heat pad on his shoulder.

“For anyone that has something, cold is never really a good thing,” Zimmerman said. “Some days feel better than others, whether it’s warm, cold, whatever. But that’s everyone in baseball. I don’t like really saying things about that, because everyone goes through stuff. It’s not really an excuse. Everyone who plays baseball has something like that.”

Zimmerman has not had many chances to make across-the-diamond throws from a standstill. On plays when he charges and makes sidearm throws, he’s been perfect. Consternation remains. Warming up between innings, Zimmerman frequently bounces the ball or pulls Adam LaRoche off first base.

Wednesday night in New York, Juan Lagares slapped a groundball to Zimmerman’s left. He scooted to field the ball, spun and heaved the ball across the diamond. The mechanics of his throwing motion did not coordinate: the lower half of his body remained static and his arm lurched forward. The throw sailed so far to LaRoche’s right he could not reach the ball even after he shuffled off the base and dove.

One National League scout who watched the Nationals frequently during spring said Zimmerman’s form when he needs to set his feet is “getting worse.” But that is probably an oversimplification.

Speaking candidly, Nationals officials will acknowledge Zimmerman’s unsettling start when it comes to his throwing. But they also see progress, and expect more to come. One said his footwork is improving. Another believes Zimmerman probably feels worse than he will admit, but continues to play because he knows how important his bat is – he’s slugging .647 through four games. They believe his throwing will come around, as it did last year.

“If feels okay,” Zimmerman said. “I’m not 21 anymore, that’s for sure. It’s just part of playing however many games you’ve played, wear and tear, things like that. It doesn’t feel bad, so that’s a good sign.”

As Zimmerman, 29, continues the work of maintaining his throwing arm, he also continues to learn a new position. Saturday afternoon during Nationals batting practice, Zimmerman took grounders at first base. He looked smooth spinning and firing sidearm throws to second base.

“I’m not as good as I think I could be yet,” Zimmerman said. “But I could definitely play in a game.”

The Braves will start left-hander Alex Wood on Sunday, a fact that was not related to Zimmerman’s work at first base. He said he didn’t know the Braves were starting a lefty, and no one had spoken to him about the possibility of Adam LaRoche receiving an off day. Zimmerman works at first two or three times per week, and Saturday happened to be one of those days.