MESA, Ariz. -- The Peoria Javelinas didn't have to be perfect to wrap up the final playoff berth in the Arizona Fall League. But they nearly were.

The Javelinas got within two outs of a seven-inning perfect game against the Mesa Solar Sox on Thursday before second baseman Zack Gelof (Athletics No. 3, MLB No. 94) lined a 98-mph fastball from right-hander Amos Willingham (Nationals) into the left-center gap for a double.

Peoria settled for a 4-0 one-hitter and a spot in Friday's play-in game against the Glendale Desert Dogs. The victor in that contest will meet the Surprise Saguaros for the AFL championship on Saturday.

Right-hander Hunter Stanley (Guardians) opened the game for the Javelinas by retiring all six batters he faced before left-hander Josh Walker (Mets) struck out the side in the third inning. Then lefty Adam Macko (Mariners) delivered his best outing of the Fall League season, preserving the perfect-game bid with five strikeouts in three frames.

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Macko allowed eight runs on 11 hits and 11 walks in his first 7 1/3 AFL innings, but permitted just one run and four baserunners in his final six frames while fanning seven. He said the key to his turnaround was regaining his feel for pitching after working just 38 1/3 innings during the regular season while dealing with a left elbow strain and an injury to the meniscus in his right knee.

Seattle's No. 8 prospect hadn’t pitched in a Minor League game since May before arriving in Arizona.

"After those couple outings where I struggled, I just wanted to come out and have fun," Macko said. "Kind of leave this place knowing that I did everything I could and I enjoyed my time here. That's when things started rolling for me."

Born in Slovakia, Macko grew up in Ireland before moving to Canada at age 12 and signing with Seattle as a ninth-round pick out of high school in 2019. Though he's still adding weight to his lean 6-foot frame, he has touched 97 mph with his fastball in the past and has advanced feel for a slow curveball in the low 70s.

Macko worked at 92-96 mph against the Solar Sox while throwing 23 of 33 pitches for strikes. He notched two of his whiffs on heaters -- including catching Top 100 prospect Jasson Domínguez (Yankees No. 2) looking at a 95-mph fastball -- one on a curveball and two on mid-80s sliders. The 21-year-old said the slider has been a point of emphasis in the Fall League.

"My slider, it's kind of slider-cutter thing," he said. "I used to have a big one that was slower and I'm trying to turn that into a hard, short slider. We'll see what it plays out to be.

"I was very happy with it today. I did lose feel for it a little bit and I couldn't throw it in the zone earlier in the season, but now it's feeling really good."

Right fielder Spencer Packard (Mariners) provided all of the offense Peoria would require with a three-run homer that struck the back of the right-field bullpen in the top of the first inning. The shot, which traveled an estimated 390 feet, came off an 89-mph fastball from left-hander Alex Ayala (Rays).

Mesa reliever Evan Reifert (Rays) wrapped up a dominant fall by striking out the side in the top of the seventh, though he did surrender his first hit of the season. He struck out 25 of the 40 batters he faced in 11 2/3 scoreless innings, overmatching hitters with a mid-80s slider with high spin rates. 

Solar Sox first baseman T.J. Rumfield (Yankees) went 0-for-2, dropping into a tie for the AFL batting title with Desert Dogs second baseman Edouard Julien (Twins) at .400.