CINCINNATI -- There were mixed feelings throughout the Cubs' clubhouse when the team traded away reliever Scott Effross at the Trade Deadline. Not only had Effross earned high-leverage innings, his easygoing personality had also made him a favorite among the players.

But it was a deal that Chicago could not pass up. The Yankees were offering a highly touted pitching prospect in Hayden Wesneski, who was viewed as MLB-ready by multiple evaluators. Still, the young pitcher knew he had to win over his new teammates when he arrived to the Cubs last month.

"I think a lot of guys told him, I'm pretty sure I told him," Cubs pitcher Justin Steele said with a smirk. "I was like, 'Hey, Effross was a heck of a guy, so you've got a lot to live up to.' I was like, 'Everybody loves Scott. He's definitely missed.'"

Wesneski took a big step in that regard in the final month, putting the final touches on an impressive rookie showing in a 3-1 loss to the Reds on Monday night. At Great American Ball Park, the righty logged six strong innings, allowing two flukey runs (one earned) and striking out six.

Facing the Reds back on Sept. 6, Wesneski became the first Cubs pitcher since at least 1901 to strike out at least eight batters in five or more shutout innings in a Major League debut. On Sept. 22 in Pittsburgh, the righty spun an immaculate inning.

Overall, the 24-year-old Wesneski finished his rookie audition for the 2023 rotation with a 2.18 ERA over six appearances. In his four starts to close out his season, the righty fashioned a 1.85 ERA with a 0.95 WHIP and .202 opponents' average, plus 22 strikeouts and five walks in 24 1/3 innings.

Wesneski was asked if there is one moment that stands out from the rest in his first taste of the big leagues.

"Oh, man, the debut is really special," Wesneski said. "You can't take that away from me. I'm a big leaguer. You can't take that. The immaculate inning, I think it's really cool, but I don't know.

"I'd rather really throw well and I'd rather pitch in the playoffs. I want to win. I like winning. And so to be honest with you, those things are all really cool, but I'd rather be pitching in October."

Effross -- an organizational success story for the Cubs, given his transition to sidearm as a Minor Leaguer facing a career crossroad -- will be pitching on the October stage with the Yankees. New York saw an arm who quickly rose to become a trusted high-leverage weapon, making the all-in franchise willing to part with a coveted starting pitcher.

Wesneski found out quickly how much Effross was missed around the Cubs' clubhouse.

"It sets the bar high for me. I mean, I've already heard it from guys," Wesneski said. "The first couple days, it was like, 'Well, we like Scotty.' I hope I fill his shoes."

Of course, Wesneski was not totally unfamiliar to people around the Cubs when the rookie joined the organization. Prior to coming to Chicago, Cubs assistant pitching coach Daniel Moskos was Wesneski's pitching coach with Double-A Somerset in 2021, and he worked closely with the pitcher throughout remote training during the '20 pandemic.

In the immediate wake of the trade, Moskos said he wished all his pitchers "could be like Scotty," but that the fact that the Cubs acquired Wesneski "makes it feel worth it." Moskos saw Wesneski's stuff, work ethic and advanced approach up close and personal.

Moskos has been thrilled to see Wesneski's initial Major League experience meet his expectations.

"A lot of the characteristics that made me so excited about him," Moskos said, "you've seen come out here. ... He's got a good head on his shoulders. He's going to identify what wasn't good, what wasn't sharp, what's the plan of attack to get it better in-between, and then go out and do it."

That will now apply to the coming offseason.

Wesneski has shown solid fastball command, combined with an elite slider. His changeup has been identified as an area for growth, especially against left-handed batters. This winter, Wesneski plans on focusing more on his physical conditioning than pitch design.

Wesneski joked that he is a "Debbie Downer'' when it comes to evaluation. He holds himself to a high standard and -- even with his eye-popping numbers down the stretch -- he’s seen plenty of room for improvement.

"The results were great, yes," he said. "It's just the way I went about it was not exactly how we wanted. Or, how I wanted. Everybody else thinks it was really good."

That includes Wesneski's teammates.

"Wessy's awesome," Steele said. "It's been a lot of fun watching him kind of step into the role he's stepped into and dominate the way he's been dominating. It's been a lot of fun."