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Top overall draft pick Bryce Harper is heading to the Arizona Fall League, where the Washington Nationals plan to tweak his batting stroke.

Harper turns 18 on Saturday, and he will join the Scottsdale Scorpions on Tuesday. He'll be a member of the taxi squad, which means he is eligible to play in games twice a week.

"I recognize that this kid is going into a situation that is pretty unprecedented. He's going to be an 18-year-old player in an extremely accelerated league," Nationals general manager Mike Rizzo said Wednesday.

"We feel the trade-off of getting this kid to work out for two months in that environment was well worth the opportunity of him struggling a little bit in such an advanced league. With this kid's ability level and this kid's attitude, it's certainly not going to retard his progress," Rizzo added. "We think the two months he'll be playing under these conditions is going to accelerate his developmental curve extremely."

The Nationals made Harper the top pick in June's draft, then signed him to a $9.9 million, five-year deal in August.

The 6-foot-3, 205-pound Harper was primarily a catcher in junior college at the College of Southern Nevada, but the Nationals plan for him to play right field.

Rizzo said Harper will start the 2011 season in the minors in Class-A ball. As for when Harper might make it to the majors, Rizzo said: "I don't have a crystal ball."

Harper played in the Florida Instructional League in September, hitting .319 with four doubles, a triple, four homers, 12 RBIs and seven walks. Rizzo already figured he would send Harper to the Arizona Fall League, but the player's performance in Florida solidified the decision.

"He did show he certainly was not over his head," Rizzo said.

Nationals hitting coach David Eckstein will spend time in Arizona and tutor Harper, who showed off his power by hitting several balls over the fences during batting practice in Washington after being drafted.

"We're going to tweak his stroke and his approach at the plate," Rizzo said.

"He's going to work on the nuances of his swing, and ... playing the outfield and just get immersed in the baseball, 24-7 — hitting, fielding, running the bases," Rizzo said.