SCOTTSDALE, Ariz. -- Key pieces of the Astros' future is how Rodney Linares, the manager of the Mesa Solar Sox in the Arizona Fall League, views a pair of prospects.
And looking at it from the standpoint of potential, it appears to be a safe bet.
First baseman Jonathan Singleton, at 6-foot-2 and 235 pounds, and George Springer, a 6-3, 200-pound center fielder, have the physical attributes and the right sort of mindsets to give Houston a boost moving forward.
"Singleton's a physically talented first baseman that can move, really good defensively, growing into his power, and he's a pretty good hitter," Linares said.
"With Springer, he's as athletic as they come, a real five-tool player. It's all about repetition with him, it's going to take a little bit of time for him to get adjusted to pitching, but we saw a short sample of what he can do during the season this year, he's got a good combination of power and speed and good defense.
"So the sky's the limit when you got guys [like those]. You can build around guys like that."
Through Tuesday's games, Springer was hitting .289 with a home run and seven RBIs, and Singleton had three home runs, seven RBIs, 31 total bases (good for second on the team) and was hitting .246.
Singleton, rated No. 26 on the MLB.com prospect list, moved up to Double-A this season with Corpus Christi in the Texas League and hit .294 with 21 home runs and 79 RBIs. He was an eighth-round choice (257th overall) of the Phillies in the First-Year Player Draft in 2009.
"I definitely feel Double-A is the hardest level I've played at so far, it's about making adjustments every day -- game to game, in between at bats and inning to inning," he said.
There is one area where he knows he has to improve, and another that neither he nor Linares thinks will be a major problem in the future: the first is improving against left-handed pitchers, the second is cutting down on strikeouts.
Singleton, in 131 games in Double-A, struck out 131 times, a figure offset by his power.
"I'm not really worried about it," he said. "I still am going to go out there and play hard every day. They come and go, so I definitely have to keep that in the back of my mind in order to keep the right mindset in order to keep from striking out, so that's definitely a big part right there."
Linares is convinced that Singleton will not be a frequent strikeout victim, based on what he has seen so far this fall.
"I think he's going to be a line-drive, gap-to-gap hitter, and he's still growing into his power, so I don't see him being a high strikeout guy," he said. "I know he struggled out here ... [but] he sees a lot of left-handed pitching, and it's something that he's going to have to work on.
"If he's going to play every day in the big leagues, he's going to hit against lefties, but you know that this league most of the relievers that come in are pretty good, so you're facing a lot of good lefties out here."
Springer, meanwhile, was a first-round Draft choice (11th overall) in 2011. He hit .316 in Class A Advanced to start the 2012 season; in six games with Corpus Christi in Double-A, his average was .216, and in his brief stay he noticed a lot of things.
"A lot of the pitchers have a lot of experience, and so do the position players," he said. "They play the counts, they play the holes, they play your swing. That was probably the biggest adjustment there."
He said that while he is happy with his progress, he still has much to learn and improve on. He views the Fall League as a good springboard to begin that process in earnest.
Springer is the 56th-ranked prospect, according to MLB.com. He said the fact that he is playing against other organizations' top players gives him the chance to raise his level of play.
"There's no particular spot that I could say I figured out," he said. "As a player, you have to get better every day, pitch to pitch, and that's my plan."
Astros hitters in the Fall League
Bobby Borchering was a first-round selection (16th overall) of the Diamondbacks in 2009. The outfielder was an average hitter in Class A Advanced, but has struggled against Double-A pitching. In four Minor League seasons, he has struck out 476 times.
Jiovanni Mier, a shortstop selected by the Astros in the first round of the 2009 Draft, blossomed in Class A Advanced this season. Prior to joining Lancaster, he never hit above .276, but in 46 games there he improved his average to .292, knocking in 25 runs in 46 games.
Astros pitchers in the Fall League
Jarred Cosart, a right-hander who was a 38th-round pick (1,156th overall) by the Phillies in 2008, made it to Triple-A this season. He was 1-2 in six appearances (five starts) with a 2.60 ERA. Cosart, who was traded to the Astros in 2011, is rated as having the best fastball and curveball in the system.
Alex Sogard has 13 starts in 92 appearances since being selected in the 26th round (783rd overall) of the 2010 Draft. He had his best win-loss mark in the Minors in 2012 once he jumped to Triple-A. He had a 3-1 record with a 3.86 ERA.
Nick Tropeano was the first player in America East Conference history to win Pitcher of the Year honors twice while at SUNY Stony Brook, where he majored in health sciences. A fifth-round Draft choice (160th overall) in 2011, he has a 6-3 record in the Minors. Tropeano is a 6-foot-4 205-pound right-hander.