MESA, Ariz. -- Hans Crouse's hard cutter/slider is one of the most unhittable pitches in the Arizona Fall League, yet he also struggles to harness it. That combination of potential and in-progress polish was on display Saturday afternoon.

Pitching for the Peoria Javelinas, Crouse struck out five Mesa Solar Sox in four innings -- all on his cutter/slider, which sat at 86-88 mph with wicked life. The Phillies' No. 4 prospect gave up four runs on three hits and four walks, though that was one of the game's better pitching performances as Peoria outlasted Mesa, 16-13.

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"He's trying to become a complete pitcher," said Javelinas coach Mike Calitri, a quality assurance coach in the Philadelphia system. "He's working on that cutter/slider against left-handers and right-handers. It's a unicorn pitch. I was coaching first base, and [Solar Sox first baseman] Jonah Bride was saying it's just a very different pitch."

The right-hander's biggest weapon got him in and out of trouble against Mesa. Less than half of his cutter/sliders landed for strikes but he racked up 10 swings and misses with it, not to mention two called strikes and a pair of groundouts. By contrast, 60 percent of his 92-94 mph fastballs found the zone, but the Solar Sox collected all three of their hits against his heater, matching the number of times they swung and failed to catch up to it.

"They just don't make contact against that cutter/slider," Calitri said. "Today was probably the least effective of his three starts and he wasn't as sharp, but he still got a lot of whiffs on that pitch. We just want him to feel good and work through some things, featuring all his offerings at any time with either-hand hitters and working on his delivery."

Acquired from the Rangers in July as part of a trade that also brought Kyle Gibson and Ian Kennedy to Philadelphia in exchange for three prospects, Crouse logged a 3.28 ERA with a .182 opponent average and 98/34 K/BB ratio in 85 innings between Double-A and Triple-A this summer. He fought his control in a pair of brief starts with the Phillies in September and owns a 7.36 ERA in three outings with Peoria. He ranks second in the Fall League with 19 strikeouts in 11 innings, though he also has issued seven walks.

The Javelinas banged out 16 hits and drew 11 walks while finishing a run shy of the season high in the AFL this fall. Two first-round picks did a lot of the heavy lifting atop their batting order. Pirates second baseman Nick Gonzales collected three hits (including a triple) with three runs and as many RBIs, while Phillies third baseman Bryson Stott notched three singles, two runs and five RBIs.

Cubs right fielder Nelson Velazquez homered for the fourth time in five games for the Solar Sox, swatting a 397-foot shot with an exit velocity of 108 mph against Mariners right-hander Luis Curvelo in the ninth inning. Velazquez is tied for the league lead in homers (five), ranks second in slugging (.808) and OPS (1.332) and third in batting (.423) and on-base percentage (.524). Blue Jays left fielder Spencer Horwitz also went deep for Mesa, tagging Mariners righty Juan Then for a 385-foot blast at 101 mph in the fifth.