WASHINGTON -- Nationals hitting coach Rick Eckstein spent last week in the Arizona and came away impressed with right fielder Bryce Harper, the first overall pick in the 2010 First-Year Player Draft, who is playing for the Scottsdale Scorpions in the AFL.

It's more than just the high batting average (.343) that drew Eckstein's attention. It was Harper's work ethic that blew Eckstein away. Harper spent the AFL season on the taxi squad, which means that he could only play twice a week. In between games, Harper worked hard on his offense and defense, and the young outfielder acted as if he was going to play every day.

Eckstein was supposed to help refine Harper's swing, but there wasn't much to refine.

"He attacks the baseball, which is great for a hitter," Eckstein said. "The days that he wasn't playing, he treated those days as if he was playing. He would go out during batting practice and get reads off the bat in right field and center field. He was working to get better in the outfield. It was impressive watching him work.

"Obviously, in batting practice, he was doing well. He was lining the ball around the park and then driving balls [over the fence]. It was very impressive on how he conducted his batting practices. He is very advanced at the plate. Mentally, he has a great feel for what he wants to do, and a great work ethic for accomplishing it."

According to published reports, Harper will start the 2011 season with Class A Hagerstown. Though Eckstein believes Harper is on the fast track to the big leagues, he declined to say when he expects the left-handed slugger to make his Major League debut.

"He has the ability to play professional big league ball," Eckstein said. "I think we would be doing ourselves a disservice trying to put that timeline together. Go into A ball and succeed. He gets a taste of coming up through the Minor Leagues. He is advanced, but he just turned 18. We have to understand that, too. I think he could compete at a high level, but you don't want to risk that developmental time mentally. I'm very impressed with every part of him as a person, as a player, the way he thinks and his commitment to excellence."