It has been about two decades since a Cubs starting pitcher has had such a highly-anticipated debut. 

Fans were buzzing at Wrigley on Saturday because Kilian is one of the best pitching prospects in the Cubs’ system. And because he came to the organization in the Kris Bryant trade last July. And because team president Jed Hoyer and manager David Ross had to play a back-and-forth semantics game for at least a week before news of Kilian’s debut became official.

But when news broke Friday that Kilian would debut, the pitcher himself actually found out the previous day on Thursday, his 25th birthday. Not only would the pitching prospect pitch for the first time at Wrigley, Saturday would be the first time Kilian had ever been to Wrigley Field.

“It was the best day ever. Best day of my life,” Kilian said. “To be able to debut at Wrigley. Saturday night against the Cardinals. […] I couldn’t ask for anything better.”

The Cubs lost to the Cardinals, 7-4, in the second game of Saturday’s doubleheader, but one of the most important takeaways from the night was Kilian’s performance. The first time through the Cardinals batting order, Kilian was perfect. In 31 pitches, he retired the first nine batters he faced.

Kilian’s command wavered in the fourth inning, and that’s when the Cardinals did their damage. He walked Tommy Edman on four pitches – an at-bat where his sinker velocity was down about two clicks from where it had been the previous inning – got Nolan Gorman to fly out, and then the heart of the St. Louis batting order took advantage of Kilian’s command issues and score three runs.

Kilian was still able to go back out for the fifth inning, and he regrouped, striking out Yadier Molina and Tommy Edman and giving up just one hit to Edmund Sosa.

“The wheels didn’t fall off,” Ross said. “He’s been a starter for a long time, and they’re going to have an inning or two like that at time to time. Just getting back on that horse. Handled that really well. Went back out and threw a lot of strikes. Really nice job.”

Killian said he got a sense that he was not using his legs as well during the fourth inning, which was contributing to the dip in his velocity and some of the command issues. During the bottom of the fourth, Kilian said pitching coach Tommy Hottovy confirmed what Kilian was feeling and gave a few tips for correcting his mechanics.

In all, Kilian finished with five innings, three runs, three hits, two walks, and six strikeouts — a very solid performance, and one punctuated by his ability to get back on the mound for the fifth inning.

When he got the news Thursday and arrived in Chicago on Friday, Kilian said he didn’t experience nerves for his first major league start until he tried to sleep Friday night.

“Last night when I was falling asleep, I could hear my heartbeat,” Kilian said.

Touring Wrigley Saturday morning helped calm his nerves, said Kilian, as did watching the first game of the double header from the dugout. Sitting in the dugout and watching while Matt Swarmer handled the Cardinals batters in the first game helped Kilian to relax, he said. It was also nice to see a few familiar faces from Triple-A Iowa, Kilian said, like catcher PJ Higgins, who caught his debut.

There is some unavoidable pressure placed on Kilian that comes from the fact that he was a part of the trade that sent Kris Bryant to San Francisco last July. Fans have anticipated his arrival at Wrigley not just because he is a good pitcher, but because they want to see some justification for being forced to say goodbye to the third baseman who scooped up the last out of the 2016 World Series.

Kilian does not see it that way, though. The added energy at Wrigley was not anything to do with him, at least not in Kilian’s book.

“I just think people come here to watch the Cubs,” Kilian said.

That Kilian’s debut came on the same day that Swarmer delivered a quality start and at the same time that Keegan Thompson and Justin Steele are carving out their respective places in the Cubs rotation might give fans reason to hearken back to the teams of the late 1990s and early 2000s. When Kerry Wood, Mark Prior, and Carlos Zambrano were all making their debuts. It might also paint a picture of what Hoyer has dubbed “the next great Cubs team” might look like. A team centered in part around homegrown pitching talent is a good place to start.

“They’ve both got good stuff. Those kids can pitch,” David Robertson said of Saturday’s starting duo of Swarmer and Kilian. “I’m looking forward to hopefully more outings just like it. They’re covering innings, they’re getting outs, they’re working fast. They’ve definitely got the makeup to be here.”