SURPRISE, Ariz. – Cleveland Guardians prospect Trenton Denholm, like many other pitchers in the recent Arizona Fall League, was adjusting to the MLB’s new automated ball-strike challenge system, or ABS, which is set to officially debut in the 2026 regular season.

But he may have the edge over other pitchers.

Denholm has added a knuckleball and sinker to his repertoire, a new approach that he thinks could help him under the new challenge system. His knuckleball is still a work in progress, but he has used the fall league to work through the kinks.

“I’ve added a few pitches, obviously the knuckleball,” Denholm said. “I’ve also been throwing a sinker a lot out here. It’s been super beneficial to me, especially to righties. It’s more pitches for the hitters to worry about.”

“ABS has helped out the knuckleball a little bit, maybe stealing more strikes from batters,” Denholm said.

Denholm said his knuckleball has only been challenged a handful of times. He is trying to find a rhythm for when to use a challenge. For knuckleballers across the league, it remains to be seen how ABS will affect them, given the amount of movement on one of the sport’s most fascinating and coveted pitches.

“I think there’s a balance, too, where there’s limited challenges,” Denholm said.

Denholm, who started 18 games this year on the bump for Cleveland’s Double-A affiliate Akron, found his groove in Arizona. The 25-year-old hurled 12 2/3 innings with a 2.13 ERA, walking six and striking out 16 in three starts.

This process is new to Denholm, but it does not change the way he attacks hitters or works through counts. Denholm is embracing the challenge system.

“It is fun for me. It definitely adds another level of entertainment for the fans,” he said. “I haven’t gotten a ton of experience with it out here, but I have had a few batters or so challenge against me.”

With ABS set to become the standard across baseball, some players may be worried about how it can change communication between players and umpires on the field. Arguments over the strike zone, which has been a part of the game since its inception, may fade away. Denholm joked that “challenging the challenge” would be an interesting tactic.

“For me, I’m always going to leave it up to the catcher,” Denholm said. “It takes some stones for a pitcher to rip the challenge. If I could change one thing about the challenge system, give me a little more top of the zone. I’d say the top of the zone got cut off a little bit.”

The automated ball-strike system is not the only aspect of the fall league that made an impact on Denholm. He used his time in Surprise not only to compete with other elite talent, but to appreciate his days on and off the field.

“Being with a new group of guys has been a blast. It’s been the best part of this whole experience,” Denholm said. “Mingling, meeting new people, creating new relationships is important to me. I always want to become a better man.”

Denholm may not be at the top of prospect rankings, but the four-year minor leaguer relishes the opportunity to pitch professionally.

With the fall league offering more exhibition-type games, the stakes are not as high as they’d normally be. For Denholm, his approach to his start days did not waver.

“Switching up from longer outings to shorter outings has been fun,” he said. “But at the end of the day, it’s still baseball, still going to compete. Me versus the hitter every time.”

As spring training is right around the corner, Denholm reflected on his time in Arizona and how it shows the Guardians what he can offer.

“Someone that is not a huge prospect like myself, it’s a great opportunity to show Cleveland what I can do,” Denholm said. “I just wanted people to see that I am a competitor. When fans see that when you pitch, it’s a good takeaway for sure.”