ALTOONA -- The morning rains had passed and, by early afternoon, the sun beat down through the humidity at Blair County Ballpark.

Near second base, shortstop Javier Guzman and double-play partner Craig Stansberry received another tutorial from instructor Jeff Manto and veteran infielder Howie Clark.

Annie O'Neill, Post-Gazette
Javier Guzman: Drawing comparisons to the Pirates' Jose Castillo.

All in a day's work for Guzman, 21, who's overcoming some defensive shortcomings and emerging as another legitimate prospect in the Pirates' organization.

"Defensively, he has a chance to be off the charts -- he really does," said Manto, the Pirates' roving minor-league hitting instructor. "He has a well-above-average arm. Once he gets the experience, he has a chance to be a good shortstop."

Guzman, 5 feet 11, 167 pounds, opened this season with Class A Lynchburg, where he made 24 errors in 69 games. While it's not surprising for a young shortstop to make a lot of errors early in his professional career -- Derek Jeter did, Jay Bell did, Jose Castillo did -- the Pirates began working seriously with Guzman at Lynchburg to get his error total down.

"A lot of things that were being addressed [at Lynchburg], we carried out the plan here as far as making him throw from different angles and throwing from where he caught the ball and making sure he used his feet and stayed low," Altoona manager Tony Beasley said. "His throws were the major concern -- never his hands. His hands have been good and solid."

Since joining the Curve June 20, Guzman has made only seven errors in 47 games and has teamed with Stansberry to give Altoona a fine double-play combination.

"He's a very athletic middle infielder and he gets to a lot of balls and gives us a lot of opportunities to turn double plays," said Stansberry, who was promoted to Altoona from Lynchburg May 3. "It's great playing with him."

"He's been really impressive," Beasley said. "Defensively, he's been outstanding. His range is real good. ... He turns the double play well."

While Guzman has improved his defense, however, his offense is another matter.

A .306 hitter at Class A Hickory last season and a .324 hitter in his Lynchburg stint this season, Guzman has a .257 batting average.

He did well in his first 20 games with the Curve, hitting .350, but since the Class AA All-Star break a month ago, Guzman has batted .170.

"He gets a little 'lunge-y' and starts drifting forward a lot, and, at this level, they start to pick up on that and pitch accordingly," Beasley said. "So he's got to make some adjustments with his approach at the plate, but it's nothing that's really that much of a concern because it's just repetition."

It might take Guzman at least another half season with Altoona next year to get that stuff "done right enough times," but nobody seems to doubt he'll accomplish it.

"He's not just a little contact guy," Beasley said. "He can drive the ball in the gaps. He can hit the ball out of the ballpark. He's a strong kid.

"But he needs to bunt more. A lot of times, he doesn't know when to take advantage of opportunities to bunt for hits. He doesn't always have to swing the bat."

As if on cue, Guzman bunted for a hit last week. Later, he smoked a run-scoring double into the left-center field gap.

"He's got some really good ability, man," Beasley said. "He's an impressive-looking kid."

"He's not just going to be a defensive shortstop," said Gary Redus, the Pirates' roving minor-league base-running instructor. "He's going to be an offensive shortstop. He's going to be an exciting player because he can run. He's going to be a guy who's going to steal you 30 or 40 bases."

"He can do a lot of things," Lynchburg manager Tim Leiper said. "He's a clutch-type hitter."

In his 69 games with Leiper, Guzman had 35 RBIs. He has another 23 RBIs for Altoona.

Because of his defensive abilities and his offensive upside, Guzman has drawn comparisons to Castillo. Castillo was Altoona's opening-day shortstop in 2003, but he soon moved to second base after a season-ending injury to the Pirates' second baseman, Pokey Reese, in mid-May that season.

"They're totally different shortstops," Manto said. "Castillo was more of presence as a shortstop. He wasn't as graceful as Guzman. When you look at Guzman, you think, 'Oh, this guy's graceful. He plays in the air. He's light on his feet.'

"Castillo was more of a raw shortstop. When you went to slide into second base with Castillo, you went in there straight into the bag because you didn't want him landing on you. Guzman is one of those guys you're going to go after because he doesn't have that kind of presence around the bag."

"Castillo was unreal," said first baseman Josh Bonifay, in his third -- and probably final -- season with Altoona. "Castillo was probably one of the best infielders I've played with. I've never seen anybody with those kind of hands. He'd make plays that you only see on 'SportsCenter,' and I guess he's making them routinely [for the Pirates] -- as a second baseman. You knew Castillo was special.

"I don't know if you can say Guzman is as special, but he has all the tools to be a good major-league infielder. I don't really see anything that's going to prohibit him from playing shortstop at a higher level."