HOUSTON -- It's been nearly a year since the Astros traded away popular outfielders Hunter Pence and Michael Bourn, a move which significantly upgraded their Minor League system and provided several of the organization's current top prospects.

While much of the focus has been on pitcher Jarred Cosart and first baseman Jonathan Singleton -- both acquired in the Pence deal with the Phillies -- another up-and-comer is having a solid season with the Double-A Corpus Christi Hooks.

Left-handed starting pitcher Brett Oberholtzer, who came to Houston in the Bourn deal last July, is 4-3 with a 4.83 ERA in 11 starts for the Hooks. In 63 1/3 innings, he's allowed 73 hits, 10 homers and 20 walks while striking out 55 batters.

"I like him a lot," Astros director of player development Fred Nelson said. "On any given night he goes out, his stuff is very good and certainly good enough to pitch in the big leagues. I think he needs to be more consistent with his command and with his stuff, and if he does, it will be beneficial."

Oberholtzer is 2-0 with a 1.38 ERA in his last two starts.

"I'm throwing the ball well now," he said. "I've still got a lot of work to do, but I'm getting back to where I need to be, and hopefully I'll be ready to go."

Oberholtzer felt at home with the Braves, the team that drafted him in the eighth round in 2008, but he understands the rebuilding Astros present a land of opportunity.

"I love the Braves," he said. "The Braves were a good organization to play for and learn from, but I feel like the opportunity over here with the Astros is going to be more beneficial in the long run. I'm taking it for what it's worth and just playing baseball."

Oberholtzer helps anchor a promising Hooks rotation that includes Jake Buchanan (3-4, 5.32 ERA), Ross Seaton (5-3, 4.28), Jose Cisnero (2-6, 4.58) and Cosart (3-3, 4.50), who's the team's top pitching prospect.

With at least a couple of those arms likely headed for Triple-A later this year -- and perhaps even the Majors within the next year -- Oberholtzer is excited about the future.

"With the pitching and some of the young players I see coming up and that I'm playing with now, we are very talented," he said. "I feel like the Astros have a good team coming up. I know they might not be seeing it now or the fans might be getting anxious, but with the next five years, we're going to bring winning back to Houston."

The Astros haven't been shy about pushing prospects through the system, promoting pitcher David Carpenter, outfielder J.D. Martinez and infielder Jose Altuve quickly last year. They aren't likely to move as swiftly with a starting pitcher, but Oberholtzer can see the light.

"It's up to me to keep pitching well and doing what I need to do and take care of what I need to do," he said. "If can do that, everything will fall into place. That's for this year. In the next couple of years, obviously I want to be held accountable to bring a winning team here to Houston. It's definitely one of my goals."

Astros' affiliates enjoying winning records

HOUSTON -- As they near the midpoint of the Minor League season, all four of the Astros' full-season clubs have a winning record. That's a huge improvement over last season, when Triple-A Oklahoma City, Double-A Corpus Christi, Class A Lancaster and Class A Lexington had a combined 235-329 record.

Oklahoma City (38-25) was in first place in the Pacific Coast League American Southern Division entering Monday; Corpus Christi (31-30) was in third place in the Texas League South, only five games out of first; Lancaster (33-31) was tied for third in the California League South, one game out of first; and Lexington (35-27) was in fourth place in the South Atlantic League Southern Division, 7 1/2 games out of first.

The Hooks, who have won four in a row, are above .500 through at least 60 games for the first time since the 2006 Texas League championship season.

"There's always winning versus development, and I think our approach is to win without jeopardizing development," director of player development Fred Nelson said. "Our managers and coaches, along with field coordinator Paul Runge and pitching coordinator Jon Matlack and our roving instructors, have done a very good job with that."

Moon surprises with rare power at Lexington

HOUSTON -- Remember Chan Moon, the Korean shortstop the Astros signed at 18 years old in September 2009?

Moon is the starting shortstop at Class A Lexington, and entering Monday, he was hitting .283 with one home run and 13 RBIs in 19 games. He hit his first homer of the season in Saturday's win over Greensboro, a three-run shot in the 10th inning to win the game that caught everyone in the organization by surprise.

"My whole phone lit up when that happened," Astros director of player development Fred Nelson said. "Moon doesn't have a lot of power, and to hit one in the 10th caught everybody's eyes throughout the network. Everyone likes Moon. So it's nice to see him doing well."

Moon, who began the year at extended spring camp, is a left-handed contact hitter who profiles as a second baseman in the Major Leagues. He played last year at rookie-league Greeneville and hit .207 with one homer and 12 RBIs in 140 at-bats.

"The bottom line is this young man has really improved his game," Nelson said. "He's gotten stronger. He's a wired kid. He still doesn't have much power, but he's got good hands and average throwing, as well as an average-to-above-average range, and [he] is very reliable."

Hessman racking up home runs in Minors

HOUSTON -- Carlos Lee's 415 career professional home runs (353 in the Majors and 62 in the Minors) are the most by any player currently playing in the Astros' organization, but there is another player in the system putting up impressive home run totals.

Mike Hessman, a 34-year-old journeyman first baseman at Triple-A Oklahoma City, socked a pair of home runs on Sunday, giving him 346 in his Minor League career. In fact, Hessman has homered seven times in the past six games for the RedHawks, including a three-homer game last week against Iowa.

Hessman, who has 17 homers this season, has 6,007 Minor League at-bats on his resume. In all, Hessman has 360 career home runs in professional baseball. He has appeared in 109 Major League games with the Braves, Tigers and Mets, and has 14 homers in 223 at-bats.

Worth noting

• Oklahoma City closer Jose Valdez blew his first save in 23 chances over the past two seasons, allowing six runs in two-thirds of an inning Saturday against New Orleans. He had allowed eight runs (six earned) all season, spanning 26 appearances and 25 2/3 innings pitched, prior to Saturday.

• Corpus Christi outfielder Austin Wates has missed four consecutive games with quadriceps tightness. The injury is not serious, and he's listed as day to day.

• Mike Kvasnicka became the first player for Class A Lexington to homer from both sides of the plate, accomplishing the feat in Sunday's 13-4 loss to Greensboro.

• Pitcher Armando Galarraga, signed by the Astros last month, started at Class A Lexington on Wednesday and allowed one run and four hits in four innings. Galarraga was scheduled to make his first start at Triple-A Oklahoma City on Monday night in New Orleans.

• The organization re-signed outfielder Drew Locke, who had three hits, including a homer, in his return to Double-A Corpus Christi on Saturday. Locke, who set a Corpus Christi club record with a .338 average and 109 RBIs in 2009, had been playing independent ball with the Sugar Land Skeeters of the Atlantic League. He filled the roster spot of outfielder Jake Goebbert, who was promoted to Triple-A.

• Corpus Christi shortstop Jonathan Villar tied a franchise record with four stolen bases in a 6-5 win over Midland on Saturday. He entered Monday with 28 steals.