But this fast?
If the 6-foot-3, 210-pounder's recent move to shortstop is any indication, Zimmerman could find his way to RFK Stadium before rosters expand in September, in an effort to help the big-league club make a push for the playoffs.
Sound a little like the kid is being rushed? Don't bet on it.
The 20-year-old, who quickly signed for $2.975 million because he didn't want to waste any time away from the field haggling over money, is not only mature beyond his years mentally, but also rich in baseball experience.
He was the MVP at the World University Games last summer in Taiwan as Team USA's third baseman, leading or tying for the club lead with a .468 average, four home runs and 27 RBIs.
Now in 52 games at Double-A Harrisburg, Zimmerman is batting .307 with 17 doubles and seven home runs.
"Moving to short is not a new thing, not a big deal at all," Harrisburg manager Keith Bodie said, downplaying Zimmerman's recent move. "He's played shortstop before."
Quite a bit, in fact, as Zimmerman patrolled the area between second and third base as a prep player and recently at Virginia, when the Cavaliers' shortstop went down briefly with an injury this past season. That would explain why when Bodie called Zimmerman into his office before a home game Wednesday to tell him the news, it was a quick meeting.
"We already know he can play third, and versatility in the Major Leagues is very important," Bodie reasoned.
As far as Zimmerman is concerned, if it gets him to Washington even faster than originally planned, it's fine by him.
"I didn't mind the move at all," the easygoing Virginia Beach, Va., native said. "They said when they signed me as a third baseman I could play short. So I expected it at some time."
The time has come even sooner than even Zimmerman expected.
Coupled with their top prospect's early success, the Nationals' brass can't be all that pleased with their current shortstop options. Starter Christian Guzman is batting just .191 (65-for-341) in 107 games and backup Jamey Carroll isn't exactly tearing the cover off the ball in hitting .239 (55-for-230) in 85 games, either.
To help ease Zimmerman's transition on the left side of the infield, the Nationals' roving infield instructor Jose Alguacil joined the Senators on Wednesday when Zimmerman first made the move.
"He's such a great athlete, he really doesn't need much work," Alguacil said. "There's some minor adjustments, but he's a special player. He'll be fine wherever he plays."
It looked that way in Harrisburg's 2-1 loss to Akron on Friday night, as the visiting Senators began a three-game weekend series with the Double-A affiliate of the Cleveland Indians. With 9,025 crammed into scenic Canal Park, the new shortstop was smooth defensively, and went 1-for-4 at the plate with a single and stolen base in the fourth inning.
"That's been the hardest transition," Zimmerman said. "Not moving from third to short, but bouncing back from an 0-for-4 or 1-for-4 night the next day. In college, there was more time in between games to make adjustments."
Aeros manager Torey Lovullo said he's already seen enough of Zimmerman to tell he's not a typical first-year player.
"He's comfortable on defense and has such a good plan at the plate -- it's nearly a slump-free approach," Lovullo said. "If he got called up now, I think he could handle it. He's a man in a [20-year-old's] body."
Stephanie Storm is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.