His manager saw the potential. This year, Tulsa Drillers outfielder Tim Wheeler is showing it for everyone.

Wheeler, a first-round pick of  the Rockies in 2009, is thriving in his Double-A debut. After hitting no higher than .256 in his first two professional seasons, Wheeler entered Tuesday’s action hitting .326 with a team-high 12 home runs and 35 RBIs out of the leadoff spot.

“I’ve just done a good job of keeping the same swing day in and day out,” Wheeler said. “And when I do have a bad day, I’m going back out the next day with the same swing and not changing something, just really trying to use my hands and not changing a whole lot.”

Wheeler’s early-season power surge puts him on a pace to become the first Texas Leaguer to hit 40 homers in a season since 1964 (Brandon Berger,Wichita). Whether Wheeler can maintain his current output remains to be seen, of course, but he’s showing the potential that Drillers manager Duane Espy witnessed first-hand as his hitting coach with Modesto in 2010.

Tim Wheeler has 12 Home Runs in 2011. Matching his season total from 2010.

“It’s been pretty special what he’s done, but I’m not surprised, because I saw what he was capable of last year,” said Espy, the veteran coach and manager in his 42nd professional season.

After the Rockies drafted Wheeler out of Sacramento State, he hit .256 with five home runs, 35 RBIs and 60 strikeouts in 68 games at Short Season Tri-City. He skipped Class A to start last season at Class A Advanced Modesto and batted .249 in 129 games with 12 homers, 63 RBIs and 114 strikeouts.

“At times it was frustrating, but it was just part of the process,” Wheeler said. “I wasn’t ready to play in the big leagues last year. You never know when that’s going to happen, but it was a lot of learning. It made me a better player, and this year I’m showing that.”

Though the strikeouts piled up and the average stayed, well, average, Wheeler showed the work ethic and commitment to winning that helped lead Modesto to the California League playoffs.

“I just try to make myself better every day, whether it be defense, hitting, base running and just being a good teammate, helping the team win really,” Wheeler said. “We got to the semis in the postseason last year, and we did a good job.”

Espy pointed out that Modesto’s 56-year-old John Thurman Field, with its deep power alleys and 400-foot center-field fence, was not always conducive to the power Wheeler has shown this year. But also, Espy noted, Wheeler is the type of player to give up outs in favor of runs.

“You had a guy on third and the infield back, he’d hit a ground ball to second and drive him in,” Espy said. “You could tell he was that type of guy. You could tell that was important. That creates a .250 instead of a .275 or .280 batting average, making outs for the team, but certainly he was a big part of us winning.”