Jake Arrieta knows what it is like to be inside Wrigley Field for Opening Day. The veteran has taken the ball for the Cubs to begin the season during his days as the rotation's ace, leader and Cy Young Award winner.

He can see it all in his mind's eye as Opening Day looms for the Cubs on Thursday.

"A lot of emotions," Arrieta said. "Nervous, positive energy. Kind of that butterfly feeling that you got as a kid."

Adbert Alzolay has pitched in the Friendly Confines -- in front of packed houses in 2019 and empty stands in '20 -- but this year will mark his first time on the Opening Day roster. He will start the season in the rotation with Arrieta, who took the young pitcher under his wing this spring.

When Cubs manager David Ross told Alzolay he made the team this weekend, Alzolay was at a loss for words.

"It just brings joy to me," Alzolay said with a wide smile in a Zoom chat on Sunday. "I was so happy. I couldn't say anything. The only thing that I said back to him was that I was so happy for getting this opportunity."

Arrieta and Alzolay provide a snapshot of the 2021 Cubs.

In Arrieta, Chicago has a veteran and a leader with plenty of accolades and a win-now mentality. The right-hander is also a walking symbol of this great era of Cubs baseball, which has a star-studded core group that could be nearing the end of its run together.

Alzolay represents the transition period that the North Siders are entering. The 26-year-old righty has the best fastball velocity on the staff at around 95 mph. He has a solid changeup and has developed a swing-and-miss slider with a different shape than his curve.

On Thursday night, Alzolay did some convincing -- taking the mound knowing he could be optioned to Triple-A -- by powering through a Dodgers lineup full of All-Stars. Mookie Betts struck out on a high heater. Cody Bellinger swung through a similar pitch. Alzolay's slider nabbed a couple more batters.

"I watched the majority of that outing," Arrieta said. "He can dominate."

Alzolay was surely monitoring Arrieta's work on Sunday afternoon, when the veteran made his final Cactus League start against the Rangers. It did not go entirely smooth -- Arrieta allowed four runs on five hits in 2 2/3 innings in the Cubs' 12-8 loss -- but the righty built up to 60-plus pitches.

Arrieta struck out four and walked one, and he was pleased enough with his command. It has been a long spring for the veteran, who has teamed with Ross, pitching coach Tommy Hottovy and other members of the pitching infrastructure on correcting delivery flaws developed in recent, injury-marred years.

"I know it was going to be a difficult beginning of the spring," Arrieta admitted. "Very fortunate for the support system that I have here. I love where I'm at. We've made tremendous strides."

That willingness to work and adapt on the part of the 35-year-old Arrieta made an impact on Alzolay, who monitored the veteran's routine and work ethic all spring. Alzolay also picked Arrieta's brain on pitching, and more recently, sought advice on his breaking balls.

Arrieta discussed different aspects of hand-positioning and grips in an effort to help the young righty create more separation between his slider and curve. The results showed up in a "B"-game setting and then again in Thursday's start against the Dodgers.

"I was excited," Alzolay said of his five-strikeout showing against Los Angeles. "Because I like those moments. I like to prove to myself that I'm good enough to be doing this and be in this position right now."

Come Thursday, Alzolay will have a front-row seat for Kyle Hendricks' Opening Day start against the Pirates at Wrigley Field. The young pitcher can watch the game unfold alongside Arrieta, who will be prepping for his season debut on Saturday.

Alzolay is currently slated to be the fifth starter behind Hendricks, Arrieta, Zach Davies and Trevor Williams.

"It's one of the biggest things that I'm looking forward to for this year," Alzolay said, "to be able to watch these guys in action -- guys like Jake, like Kyle Hendricks. I feel that those two guys have really influenced my career so much in so short a time right now."

Arrieta is looking forward to having Alzolay at his side, too.

"I'm very happy for him," Arrieta said. "I look forward to continuing to work with him and watch him grow. He's nowhere near where he's going to be and that's a good thing. He's in a great place. He's only going to get better.

"He's a tremendous student of the game. He prepares himself extremely well and there's still room to grow. And I'm in the same boat -- I feel like I can grow, as well."