Ryan Zimmerman. (AP Photo/Nick Wass)

Four hours before Monday’s game at Miller Park, Ryan Zimmerman stood at his old position, fielded ground balls and threw across the diamond for the first time since he returned from the disabled list three weeks ago. Nationals Manager Matt Williams has said for weeks that Zimmerman could return to third base when Bryce Harper comes back from injury — perhaps around July 1 — but that process began in earnest on a cool afternoon in Milwaukee.

Zimmerman scooped up groundballs and fired across the diamond with relative ease. His worn right shoulder had pushed him to left field while Anthony Rendon played the position he manned exclusively for the Nationals for the previous nine years. After years of playing and injuries, playing third and throwing went from second nature to a challenge, forcing him to make side-arm throws even on routine plays this season.

But on Monday, Zimmerman fired balls overhand and from a three-quarters arm slot comfortably. Not all of his 20 to 25 throws zipped across the diamond, but Zimmerman looked more at ease than before his thumb injury on April 12. “Before I broke my thumb I was pretty much throwing underhand,” he said with a laugh.

“Everything felt good today,” he added. “It felt really good. I’ll continue to do it. I don’t think we’ll do it every day but certainly do a little bit more. And if I do need to go over there, if I do play over there, I’ll be ready.”

The time away from third had allowed Zimmerman to rest his shoulder and may have helped his throws on Monday, Williams said.

“He threw the ball across fine,” Williams said. “No problems. And looking to get his legs in shape to do that, too.”

According to Williams, the Nationals will rotate players through various positions. Harper can play all three outfield position, and may push Denard Span to the bench if he plays center; Zimmerman would to play left, third or first; and Rendon would play third or second, which would send Danny Espinosa to the bench. There are several defensive combinations and Williams said he isn’t prepared to detail how much each player will play each position. It will be a careful balancing act for Williams to execute.

“Everybody is speculating at this point about what’s going to happen and we don’t know yet,” Williams said. “We don’t know where he’s going to play on any given day or night, and frankly can’t tell you. He’s working in left, he’s working at third and he’s willing to play anywhere he’s asked to play.”

Zimmerman has come to grips with the reality that third base is no longer his exclusive position. He even enjoys his new-found versatility and doesn’t mind rotating between three spots. Zimmerman said doesn’t care how much third base he plays when Harper returns.

“The goal is to win and if that gives us the best chance to win that’s what I’ll do,” he said. “Everyone expects me to be upset or that I should feel disrespected for being asked not to play third. I don’t know why people look at it that way. I played third for a long time and played it pretty good. And now, I’ll play somewhere else. I don’t really think too much into it. I think other people try and make too much out of it.”