The Mets' top prospect turned in his second solid performance Saturday night, allowing one run on two hits over six innings in Buffalo's 5-1 loss to visiting Scranton/Wilkes-Barre.
Wheeler surrendered hits to two of the first three batters he faced, with Eduardo Nunez delivering an RBI double to open a quick 1-0 lead. But that was all the Yankees could muster against the two-time All-Star Futures Game selection, who did not yield another hit over his final five frames.
The 22-year-old right-hander walked back-to-back batters in the sixth but stranded both runners by getting Nunez to bounce into an inning-ending double play.
"I think I did well," Wheeler said. "The last inning of the past two games, I've struggled a little bit. I need to work on staying down on my pitches. Late in the game, I've been having some pitches go high on me a bit, but I just need to keep taking the time to work on my mechanics and improve on the little things."
After making 19 starts in the Eastern League, Wheeler said he has noticed differences at the highest level of the Minor Leagues.
"I think the hitters are a little more patient," he said. "They don't swing at curveballs down out of the zone and stuff like that. The strike zone is a little tighter, of course, the umps call a tighter game, but I have Mike Nickeas behind the plate calling a great game for me and I feel really confident going forward."
Wheeler was 10-6 with a 3.26 ERA with Binghamton, the highlight coming in the form of a six-hit shutout against Erie on July 14.
In his International League debut on Monday, the Georgia native needed 101 pitches to get through 4 2/3 innings. He surrendered two runs on three hits and four walks while striking out seven in a no-decision at Syracuse.
Bisons manager Wally Backman said he's already noticed improvements in Wheeler.
"I think it was better tonight," Backman said. "He looked more comfortable out on the mound. He commanded the strike zone better. Sometimes he got a little erratic even tonight, but he's a young kid with a great arm. He's going to be real good someday.
"Once he is able to command his fastball to both sides of the plate and keep it down, he's going to be pretty darn good."
The Bisons did little to help their starter out, getting only an RBI groundout from Josh Rodriguez in the fifth.
Brandon Laird put the Yankees ahead for good with a solo homer in the seventh off reliever Dylan Owen (4-9). Ronnier Mustelier capped a three-run ninth with a two-run homer, his ninth.
Reliever Kelvin Perez (1-0) yielded one hit over 2 2/3 scoreless innings to pick up the win.