For most baseball players, a year of lost development would be a huge speed bump on the road to big-league stardom.

Adbert Alzolay is not most players and he continues to prove that each time he takes the ball in the Cubs rotation.

While most of the baseball world was just figuring out how to survive in the summer of 2020, the 26-year-old right-hander was thriving.

After a two-week stint on the injured list for a blister, Alzolay returned Monday night to help solidify the Cubs rotation.

“Adbert’s a really big part of our success,” David Ross said. “He’s obviously a huge piece for us and pitching big innings for us. He’s given us a chance to win and continues to grow every time out.”

There are many reasons to credit for Alzolay’s strong start to the 2021 campaign but his success actually started last summer, at the Cubs’ alternate site in South Bend.

For Alzolay, the pandemic-induced shutdown may have been a blessing in disguise. That’s when he developed his slider that has become a “game-changer.”

Alzolay is throwing that pitch nearly half the time (46.3%) and it rates as an elite pitch. The Cubs approached him last summer about adding the slider, looking for a weapon he could use to neutralize left-handed hitters.

“I’m always open to try new things,” Alzolay said. “The way that they put it on the table to me, it was awesome. That pitch they told me, ‘it will open so many doors for you.'”

Cubs vice president of pitching Craig Breslow was the one who first introduced the slider to Alzolay and the two had conversations nearly daily about the pitch and the young right-hander’s development.

“He would give me the data information that he got about the pitch and compare with other pitchers that throw the same pitch,” Alzolay said. “And then just trusting that.

“He put a lot of confidence on it, too — ‘just let it rip, throw it right down the middle. The pitch is going to work right there. With your arm speed and the way that you work, the way that your sinker is working, you don’t need to throw that pitch for chase all the time. You can get guys out with the pitch in the strike zone.'”

The Cubs initially tried to tinker with Alzolay’s curveball, aiming to add velocity. But that didn’t work with his grip, so he continued to play around with it in his daily catch sessions, searching for the right feel for the slider.

Once he found a comfortable grip and release point, it was a matter of developing the slider into a pitch that he could not only utilize in games but actually lean on to get big-league hitters out.

That’s where Ron Villone comes in.

Villone was set to become the Cubs’ Triple-A pitching coach in 2020 before the shutdown threw a wrinkle in the mix. When baseball resumed, Villone was sent to the alternate site to help the organization’s young pitchers without the benefit a minor league season.

Last summer was the first time Alzolay had worked closely with Villone but the former 15-year MLB veteran made an immediate impact.

“He was the one that gave me more confidence to throw my pitches,” Alzolay said of Villone.

Ask any pitcher and they’ll tell you the hardest part about adding a new pitch is finding time to work it into the mix. There are only so many throws allotted for each player on a given day and pitchers need to utilize their time fine-tuning their delivery or working on other offerings.

When Alzolay was done with his bullpens or long toss for the day in South Bend, he would continue to try out his new slider but had trouble finding a partner to play catch with. None of his teammates wanted to go out there and stand in front of Alzolay’s slider and 2-seamer with all the movement.

But Villone was willing to grab a glove and play catch anytime Alzolay asked.

“When people start playing catch with Adbert and start seeing his slider and his 2-seamer, you start seeing fear in his teammates’ eyes,” Villone said. “Like, this thing is so nasty. It’s not that easy. I had to take a deep breath a couple times, take him in the corner and say, ‘hey, throw it as hard as you can. Let it rip, son. Let it rip.’

“And he took off. It was like a fighter pilot getting in a jet. That’s what he was putting in his hand. Watching it develop, we knew it from Day 1. It was just a matter of him believing in it, finding ways to use it, finding ways to find that confidence.”

Like Alzolay’s teammates, Villone wasn’t exactly relishing the opportunity to stand across from the young right-hander and try to catch the slider. But he knew how important the pitch was to Alzolay’s development.

“I was fortunate enough, he only hit the glove,” Villone said. “Maybe hit a toe a couple times, but I kept my teeth. His teammates started watching him control it a little bit better and he was able to start throwing it to everybody. And now the sky’s the limit. What a worker.”

When Alzolay started incorporating the slider into live bullpens against his teammates at South Bend, he was willing to throw it six or seven times in a row if necessary.

Since it wasn’t game action in South Bend, Alzolay had a singular focus — get the slider big-league ready.

He also had to develop the pitch while bouncing between the alternate site and the big leagues last summer. But he made sure to use that to his advantage, picking the brains of the veterans around him.

“I was experimenting with the pitch but as soon as I started throwing it, the first one that came up to me was [Yu] Darvish and he started asking me like, ‘how do you grip it? What are you doing?’” Alzolay said. “And he started giving me tips, like ‘you know if you move this finger or your thumb a little bit more, you can gain or erase velo on the pitch.'”

Darvish is a master at manipulating his pitches, often having two or three different versions of a particular offering. He passed that on to Alzolay, showing the younger pitcher how to add or subtract velocity or depth on the slider.

Alzolay continued that progression in spring training this year, shadowing Jake Arrieta and spending hours talking pitching with the former Cy Young winner.

“As soon as I started learning all those things and putting in work in my bullpens during spring training, having Jake there with me, telling me like, ‘OK, now throw it this way, now throw it back door, now do this,'” Alzolay said. “Same with Kyle [Hendricks]. Having all those guys here and the coaching staff that we have, I feel that’s been the key for the pitch to develop so quick too.”

Beyond the slider, the Cubs are enjoying Alzolay’s development this season. Ross believes the right-hander is learning a lesson seemingly every start out.

Early this month against the Padres at Wrigley Field, the focus was on Alzolay controlling the running game. At the beginning of the season, it was about working through jams and getting beyond the 5th inning.

Cubs pitching coach Tommy Hottovy was particularly impressed with Alzolay’s growth in an outing against the Cardinals in St. Louis on May 22.

Cardinals veteran catcher Yadier Molina began the 7th inning with a go-ahead homer off Alzolay. But the Cubs starter didn’t let that throw him off his game and needed only 7 pitches to dispatch the Cardinals in the rest of the inning and get his offense back to the plate.

“That was the loudest we heard fans in the stands, people going ballistic — Yadi came out for the ovation,” Hottovy said. “[Alzolay] didn’t execute a slider he wanted to execute — homer, the crowd’s going ballistic — and he threw 7 pitches and got 3 outs right after that.

“That’s impressive. That’s something that you don’t learn unless you go through it. That was pretty cool to see.”

Those are the kind of building moments the Cubs love to see from Alzolay throughout his first full season in the big leagues.

They’ll continue to monitor his workload as the season wears on but there is no specific innings limit set forth by the organization.

For now, the Cubs will keep handing Alzolay the ball every fifth day and hope he can continue to help lead the rotation in the fight for the NL Central.