HOUSTON -- Astros director of player development Fred Nelson recently returned from a trip to the Astros' Class A affiliate in Lancaster, Calif., where he got the chance to see some of the club's top prospects up close and personal for a few days.

Perhaps the thing that stood out to Nelson more than anything else was the effectiveness of the pitching staff. The numbers, which show Lancaster last in the California League with a 5.03 ERA through play Sunday, don't provide a true indicator of how well the staff has thrown in a very favorable hitter's environment in Lancaster. The team ERA is nearly a run better than it was at the end of last season.

"I was really surprised at how well that club was able to pitch at home in this offensive environment," Nelson said.

Right-hander Ruben Alaniz, signed by the Astros as a non-drafted free agent out of south Texas nearly three years ago, threw seven scoreless innings Friday night to lower his ERA to 2.90 while improving to 2-0. Starter Bobby Doran (2-1, 3.30 ERA) has also pitched well.

The secret to Alaniz's success was pitching down in the zone and getting ground balls. Only four of the 21 outs he recorded were via fly balls, which Nelson said is the key to success in Lancaster.

"They're getting more ground balls than I've seen before out here, which obviously in that environment is a positive thing," Nelson said. "They've been more aggressive pitching in, and we talked about that this spring. The group of guys that goes out to Lancaster can't leave the ball out over the plate to right-handers so they can lift the ball into the jet stream."

Lancaster center fielder George Springer, the Astros' No. 1 Draft pick last year, was hitting .278 with two homers and 18 RBIs in 97 at-bats through the weekend. Nelson walked away impressed with him and shortstop Jiovanni Mier, third baseman Jonathan Meyer, first baseman Telvin Nash, catcher Rene Garcia and left fielder Enrique Hernandez.

"You've got a nucleus of a pretty good Minor League team and with that a nice little group of prospects as well," he said.

Nash has cooled off somewhat following his torrid start and was 7-for-39 in a 10-game span ending Sunday. Three of those hits were home runs, giving him nine for the season.

Minor League roster moves forthcoming

HOUSTON -- With the Minor League season about a month old, the Astros could begin to start shuffling some players to different clubs, but don't expect any eye-opening promotions or demotions just yet.

The Astros made several roster moves within the organization in the last few days that became necessary when pitcher Jordan Lyles and infielder Brian Bixler were called up to the Major Leagues out of necessity. Director of player development Fred Nelson said some moves that aren't related to injuries or filling roster spots could begin to happen soon.

"We kind of have a feel of what the clubs are like and if they're competitive," he said. "You've seen enough of the league in most cases. Sometimes the way the schedule is you haven't seen [other teams in the league] and maybe you haven't seen the best four teams and maybe you haven't seen the worst four teams.

"We have a pretty good feel of who we've got where and if we've made any mistakes and if guys are in places they shouldn't be. It's just more tweaking and making sure we have the guys in proper spot."

Worth noting

• Oklahoma City outfielder J.B. Shuck, one of the last cuts from spring camp, was hitting .400 (16-for-40) in his previous 10 games entering Monday. Half of those hits came in the previous two games, when he went 8-for-10 with two runs scored Saturday and Sunday against Round Rock to raise his batting average to .333.

• Corpus Christi first baseman Jonathan Singleton, who blasted two home runs on Tuesday, had his 10-game hitting streak snapped with an 0-for-4 on Sunday at Frisco. He's hitting .350 with three homers and 13 RBIs in 80 at-bats, including .431 against right-handers (.207 against lefties).

• Right-hander Josh Zeid came off the disabled list Saturday and threw a scoreless inning in his first action in more than two weeks. He had been sidelined with elbow tenderness.

• Corpus Christi manager Keith Bodie is two wins shy of reaching 1,000 in his career. He has a 998-935 record in 16 seasons as a Minor League manager, including a 318-257 record in the Texas League with both Wichita and the Hooks.