BOSTON — After his rapid rise to the majors, Jackson Holliday was given a particularly meaningful number with the Baltimore Orioles.

Baseball’s top-ranked prospect made his big league debut Wednesday night at Fenway Park, starting at second base and batting ninth against the Boston Red Sox. He struck out swinging his first time up and finished 0-for-4 with an RBI groundout in the sixth. The Orioles won 7-5.

The 20-year-old infielder, selected No. 1 overall in the 2022 amateur draft out of high school in Oklahoma, is a son of Matt Holliday, a seven-time All-Star and the 2007 NL batting champion.

“Nervous? I mean, a little bit. Not too bad,” Jackson Holliday said before the game. “I’m not as nervous as I thought I would be. I’m more excited. Kind of changed the mind frame from nervous to excitement. But yeah, I’m really excited.

“I got a taste a little bit during spring training. Obviously, this will be different now during the season, but I felt like I was able to hold my own and definitely looking forward to tonight.”

Holliday will wear No. 7 for Baltimore. His father wore that number during seven seasons with the St. Louis Cardinals and one with the Colorado Rockies. But it hadn’t been worn by a member of the Orioles since former manager Cal Ripken Sr. was still coaching in 1992.

One of his sons, Billy Ripken, was the previous Baltimore player to wear that number, in 1988. The Ripken family, Orioles royalty, gave its blessing to the young Holliday.

“Our family is thrilled that @J_Holliday7 will be wearing dad’s #7,” Hall of Fame shortstop Cal Ripken Jr. posted on the social platform X. “Excited to watch him play!”

Holliday, who turned 20 on Dec. 4, became the second-youngest player in the majors behind Milwaukee outfielder Jackson Chourio, who turned 20 on March 11.

“A guy making his major league debut is always exciting,” Orioles manager Brandon Hyde said. “It’s exciting for everyone. It’s going to be fun to watch. I’m excited for the kid, excited for the family. It’s a real, real special day. It’s an overwhelming day for Jackson. I just hope that he relaxes as much as possible.”

A left-handed hitter, Holliday was drafted as a shortstop less than two years ago out of Stillwater High School and advanced through four minor league levels in 2023. He had a tremendous spring training with Baltimore this year, batting .311 with a .354 on-base percentage and .600 slugging percentage in 15 games.

But general manager Mike Elias wanted Holliday to get more playing time at second base and more experience against left-handed pitching. Just before the end of camp, Holliday was sent down. In 10 Triple-A games this season, he hit .333 with a .482 on-base percentage and .595 slugging percentage.

That time in Triple-A paid off, Holliday said.

“Yeah, I think getting at-bats. I got a lot of at-bats because we scored a lot of runs,” he said. “I was able to get pretty comfortable. My swing’s in a good spot, put together a lot of good at-bats versus lefties, which we knew was kind of more of the purpose of being down there. And, it doesn’t hurt to play.”

Primarily a shortstop, Holliday made 33 minor league starts at second base, including eight this season. Gunnar Henderson, the reigning AL Rookie of the Year, plays shortstop for the Orioles, so Holliday will get most of his time at second.

He started a 4-6-3 double play to end the second inning Wednesday.

“There’s a lot to process and there’s a lot of hype,” Hyde said. “Hopefully, he can just relax, think confidently and have fun out there.”

That was Holliday’s plan.

“Just to get comfortable. After the first pitch or first groundball or however it is, I think I’ll be fine,” he said. “I’m just going to try to hit the fastball back where it came from and go from there.

“It’s different. It’s a lot. I feel like I’ve been born to handle that, and to be here and play baseball for a long time.”

Baltimore selected Holliday’s contract from Triple-A Norfolk. To make room for Holliday on the roster, utilityman Tony Kemp was designated for assignment.

Told of his promotion after his Triple-A game Tuesday night, Holliday phoned home with the news.

“It was a really cool moment to be able to call my dad and tell him to find his way to Boston,” he said.

Matt Holliday batted .299 with 316 home runs and 1,220 RBIs during 15 major league seasons with the Rockies, Athletics, Cardinals and Yankees from 2004-18.

Along with his father, Jackson Holliday was expecting his grandfather Tom Holliday, a longtime college coach; his wife, Chloe; his mother; and his brothers and sister at Fenway Park for his debut.

The youngster hadn’t had time to go through all the texts he’d received wishing him good luck. But there was one from a Maryland native that stood out.

“My dad showed me a text message from [Olympic swimmer] Michael Phelps,” Jackson Holliday said. “So, that was kind of cool.”

The Associated Press contributed to this report.