The version of Hayden Wesneski we saw walk off the mound in the 7th inning Wednesday is a much different version than we saw at the outset of Spring Training.

It’s not a drastic difference on the mound or with his repertoire, even though the results are vastly different.

The change has all come internally, as Wesneski has a brand new outlook and mentality — and the Cubs are reaping the benefits.

Wesneski was not one of the 13 pitchers on the Opening Day roster. He didn’t necessarily know it at the time but that was actually the best thing for him.

“I needed to start in Triple-A,” Wesneski said last week. “I was not in a good headspace. I didn’t think my mechanics were right and some of the guys were like, ‘man, you should’ve made the team.’

“No, I did not deserve to make the team. And that’s the honest truth. I wasn’t pitching well and I needed that time.”

It was something Craig Counsell and the Cubs coaches identified early on — that Wesneski was an important part of the pitching staff but he still needed some development.

“He was a little frustrated pretty early in spring about how he felt and you could sense he was a little frustrated,” Counsell said. “Even before he started pitching in games, you could feel a little frustration almost.”

Wesneski acknowledged that he was frustrated this spring.

Frustrated at the way the ball was coming out of his hand, even playing catch. Frustrated at not getting the results he wanted.

And a little bit of it was frustration of the circumstances he can’t control.

Wesneski made the 2023 Opening Day rotation but ended up spending the last few months of the season shuttling between the minors and majors and mostly working out of the bullpen.

He wants to be a starting pitcher, as do most young pitchers who have spent their whole career in that role — and found some success at the big-league level.

Yet the Cubs added Shota Imanaga to the rotation over the winter to pitch alongside Justin Steele, Jameson Taillon and Kyle Hendricks. That left Wesneski among the arms battling for the final rotation spot — which eventually went to Jordan Wicks. (Javier Assad also won a spot in the rotation after Taillon ended up on the IL to start the year.)

So Wesneski started this year in Triple-A and quickly set about turning his mindset around.

“I was trying to get feelings that weren’t right,” Wesneski said. “I was getting frustrated with things that I didn’t need to get frustrated with. And I was trying a little too hard on certain things.

“The adjustment I made at Triple-A and moving on with the season is relaxing. Your stuff is really good and trusting it and get a line and throw it. The mechanical adjustments are what they are. At the end of the day, a lot of it is confidence.”

The version of Wesneski we see now is certainly confident.

The 26-year-old right-hander entered Wednesday’s start having allowed only 1 earned run in 16.2 innings.

On Wednesday, he faced a tough Padres lineup and while he did surrender 3 runs, he pitched into the 7th inning and turned in his 2nd straight quality start.

Wesneski now has a 1.59 ERA and 0.88 WHIP on the season while filling an important role for the Cubs.

When he was first called up on April 17, he saved the bullpen with a strong effort — 4 shutout innings. He was credited with the win for his efforts, but ultimately sent back down to Iowa right after.

After injuries struck with Hendricks and Drew Smyly landing on the IL, Wesneski came back up and worked out of the bullpen again before entering the rotation in a spot start when Wicks emerged with a strained forearm.

On Friday, he shut down the Brewers for 6.1 shutout innings, striking out 8 batters and only allowing 5 baserunners (3 hits and 2 walks).

Wesneski points to improved fastball command and getting ahead of hitters as two keys to his success. But it all comes back to confidence.

“[Having success in the big leagues] helps for someone like me that has moved up and down,” Wesneski said. “It just confirms that I should be here, right? I should pitch in the big leagues.

“And it also gives me a checkpoint like, ‘hey, you’re doing the right stuff. You’re doing the right work. Continue to do that and monitor the situation because at some point, it could go a different direction.’”

Counsell understands young pitchers don’t all take the same path to big-league success. In Milwaukee, he helped oversee players like Corbin Burnes, Brandon Woodruff and Freddy Peralta emerging from inconsistent young arms to Cy Young candidates.

One of Counsell’s strengths as a manager is an ability to see the big picture for his team even while in the middle of the day-to-day grind of a season. And in the big picture, Wesneski can play a key role for the 2024 Cubs — whether in the rotation or bullpen.

“Hayden’s a very normal young pitcher, just making his way forward in the game,” Counsell said. “And that comes with some uneveness at times. That’s OK, right? And that’s learning. He’s learning during this process.

“It’s fun to watch if you can kinda back off it a little bit and not be stuck right in the emotion of it. He’s learning as we go here and every person and every player learns in a little bit different way.

“But the journey so far, Hayden’s fully vested in it and it’s his journey. It’s going maybe different than Javier Assad’s journey but it’s going in the right direction in a big picture.”