In moving Bryce Harper straight to Class AA Harrisburg, the Nationals want to give their phenom more of a challenge. It leaves him two steps from the major leagues. (Timothy Jacobsen/AP)

The Washington Nationals promoted Bryce Harper to Class AA Harrisburg from Class A Hagerstown, bypassing high-A Potomac to provide him an adequate challenge and putting him two steps away from the major leagues.

Harper, the 18-year-old phenom the Nationals drafted with the first overall pick last year, hit .318/.423/.554 with 14 home runs, 19 stolen bases and 44 walks over 72 games and 258 at-bats. After he dealt with nagging injuries, particularly a bone bruise near his left thumb, the Nationals decided he was ready for the next step in his development.

“Right about now, he needs another challenge,” Manager Davey Johnson said. “Double A is the perfect spot.”

In his debut Monday night, Harper started in left field and went 2 for 3 with two singles, a walk and a run. The Senators drew 8,092 fans to Metro Bank Park, a record for the stadium, and beat Erie, 8-1. Catcher Derek Norris, a top Nationals prospect whom Harper played with last year in the Arizona Fall League, went 3 for 4 with two homers.

General Manager Mike Rizzo said earlier in the day that “it’s safe to say” Harper will remain at Class AA for the remainder of the season, and then proceed to play every day at the Arizona Fall League. Rizzo also said “it’s important for him to play at every level in our minor league system.” So, presumably, Harper will begin next year at Class AAA Syracuse and not open the 2012 season in the major leagues.

Rizzo decided to send Harper to Harrisburg, and not Potomac, because he felt Harper had taken enough at-bats in Class A, whether it be low-A or high-A – “he’s already played the A level,” Rizzo said. “We want to give him a month and a half in Double A.”

Said Johnson, who has known Harper since he was 15: “The competition at Double A is right where he should be. He needs to be challenged. Bryce is never going to bite off more than he can chew. I know where he wants to be right now. If he left there, he wants to be up here. Don’t tell him I said that, but I know that’s what he’s thinking.”

Potomac’s Pfitzner Stadium also has a notoriously poor field, where drainage issues often lead to rainouts on sunny days that follow rainstorms. When asked why Harrisburg better suited Harper than Potomac, Johnson, clearly joking, said “the field’s in better shape.”

Some in the Nationals’ minor league system believe, in seriousness, the field condition contributed to Harper heading to Harrisburg. Rizzo emphatically said Potomac’s field had no impact on the decision.

“Absolutely none,” Rizzo said. “This is a developmental issue. We’re happy he progressed as much as he did in that league. We feel he’s ready to take the next to Double A. This is a plan that I had in place in my mind for a long, long time.”

Harper played only center field and right field at Hagerstown, but he will play primarily left field at Harrisburg, Rizzo said. The Nationals want Harper comfortable with all three outfield spots, thereby allowing them to slot Harper into their outfield no matter how it’s constructed when he comes to the majors.

“We feel that he’s going to be above average at any one of those positions,” Rizzo said. “The way the roster is comprised at the time when he gets here will kind of dictate where he plays.”