But Muncy, the A's No. 16 prospect, has corrected some of the flaws that initially hampered him and says he feels much more comfortable now. After going 2-for-3 with a walk Tuesday, Muncy is hitting .350 in his last seven games and has raised his batting average to .224 this fall.
Muncy helped Mesa to an 8-1 victory Tuesday against Peoria at HoHoKam Stadium. The Solar Sox extended their winning streak to four games and maintained their half-game lead in the East Division with two games to play.
Muncy said he thinks his struggles early in the fall were a result of taking too much time off after the end of the regular season.
"It was a matter of getting my old swing back," Muncy said. "My swing didn't feel right after first couple games here. I thought it did, but it didn't and it ended up costing me. I think I'm getting my swing back now."
That swing helped convince the A's to select Muncy out of Baylor in the fifth round of the 2012 First-Year Player Draft. He has moved quickly since, reaching Double-A Midland in his first full professional season.
Muncy played well this year and led all A's Minor Leaguers with 25 home runs in 140 games between Class A Advanced Stockton and Midland. But he said the most important lesson he learned as he transitioned to the professional ranks was just how long the season can be.
"You can get tired pretty easily," Muncy said. "You have to go out there every day with a routine. It's tough to go out there if you're not prepared the same way every day. There's a lot of patterns you've got to pick up."
Tuesday, Muncy continued that long season and contributed to Mesa's full-team effort at the plate. All of the Solar Sox starters had at least one hit or scored a run. They combined for 10 hits and six walks. First baseman C.J. Cron, the Angels' No. 2 prospect, went 2-for-4 with a home run. He raised his batting average to .405 and is tied for second in the AFL with five home runs.
Peoria's offense, meanwhile, was smothered for the second day in a row by Mesa. The Javelinas were held to four hits Tuesday and scored their lone run thanks to a pair of walks, defensive indifference, a balk and a passed ball, all with two outs in the eighth inning. The run snapped their 21-inning scoreless streak.
Solar Sox starter Blaine Hardy allowed four hits and struck out three batters in four innings. Five relievers combined for five no-hit innings following the left-hander.
Mesa will play a home-and-home series with Glendale, while second-place Salt River plays Scottsdale. The division winner will play Surprise -- which clinched the West Division on Monday -- in Saturday's AFL championship game.
The Solar Sox are trying to complete a near wire-to-wire run in first place in the East and don't want to see their lead slip away now. Muncy said they just need to keep playing the way they have throughout the fall.
"Just stay nice and loose out there," Muncy said. "We've got a great group of guys. There's not any bad attitudes out there. I know we've only been together a month and a half, but we all like each other and I think that's been a key to our success.
"We've just got to keep being ourselves."