PEORIA, Ariz. -- The Padres felt Fernando Tatis Jr. earned their starting shortstop job this spring. Forget the service-time implications -- he'll be in San Diego for Opening Day.

Tatis -- the sport's No. 2 prospect and a 20-year-old with five prodigious tools -- will be promoted to the Padres before their season opener against the Giants on Thursday afternoon, according to general manager A.J. Preller.

By promoting Tatis for Opening Day, he will be eligible to become a free agent a year sooner than he would have otherwise been if the Padres waited until April 12. But Tatis' status in 2025 is a discussion for another day.

In 2019, the Padres are going for it. They own the sport's best collection of prospects, and their Opening Day roster will be full of them. Along with Tatis, catcher Francisco Mejia and right-hander Chris Paddack have also been informed they've made the big league club.

• Mejia earns spot, will share time with Hedges

“This was a baseball decision, and we decided to make it that way,” Preller said. “Obviously you factor in everything. You factor the roster, the budget and finances. But ultimately from a baseball standpoint, this was the direction we wanted to go in. … He makes us a better club. We wanted to reward him for that.”

Tatis will line up next to star third baseman Manny Machado, who signed a record-setting 10-year deal with San Diego in February. Machado and Tatis have become close this spring, and perhaps fittingly, they will be together on the left side of the infield for their respective Padres debuts on Thursday.

Born Jan. 2, 1999, Tatis will be the youngest Padres player in history to play on Opening Day, at 20 years, 85 days old. The last player so young to start for any team in its opener was Adrian Beltre in '99, at 19 years, 363 days old with the Dodgers.

Tatis would be the eighth-youngest position player to start on Opening Day in the past 50 seasons -- six individuals did so, including Robin Yount twice. Overall, 31 different position players have started Opening Day at Tatis' age or younger in the Modern Era (since 1900), according to the Elias Sports Bureau.

"I feel like I'm ready,” Tatis told MLB.com on Monday. “I feel like I'm ready to go. I don't know. We'll see what it's going to be. I'm not saying everything is going to be 100 percent perfect right away. In this game, you learn every day and you just make adjustments."

Tatis has the chops to back it up. A career .280/.358/.487 hitter, Tatis has raked at every level of the Minor Leagues. In the Dominican Winter League, he led Estrellas Orientales to their first title in 51 years. (The Padres, by the way, are about to enter their 51st season without a championship.)

“In the offseason and in Spring Training, he answered a lot of questions for us,” Preller said. “We know he's going to be a young player in the big leagues, and there's always an adjustment period. It's the highest level. He's going to get challenged. But he's got the ability and the makeup and the work ethic, in the end, to handle that.”

Signed by the White Sox in 2015, Tatis joined the Padres before he had even played a Rookie League game for Chicago. With the White Sox fighting for a postseason spot, they dealt Tatis and righty Erik Johnson to the Padres for veteran right-hander James Shields.

Tatis quickly ascended the prospect ranks, eventually reaching the top spot among shortstops and among Padres. Only Vladimir Guerrero Jr. checks in above Tatis on MLB Pipeline’s list.

Still, Tatis’ promotion seemed unlikely for much of the spring. He has yet to play a full season at Double-A, after his 2018 campaign was cut short when he broke a bone in his left hand while sliding into second.

But Tatis acquitted himself well enough in the Cactus League. This spring, he batted .241/.317/.444 -- a relatively mundane slash line. But his incredible talent was on full display with a pair of rocket home runs, some elite speed and aggression on the bases and steady defense at shortstop. On Friday, he scored from first base on a single, a play that turned heads across the sport.

“He can help our team win in so many different ways that the value's not just tied to the bat,” Preller said. “There are a lot of different ways he can win a ballgame for you.”

Having just spent a franchise-record sum on Machado, Padres decision-makers feel it's time to win now. San Diego hasn’t made the postseason since 2006 and hasn’t had a winning record since ’10. Within the organization, there’s an intense desire to buck those trends as fast as possible, and that meant promoting Tatis to help do so.

The youngest Padre to play a game since Roberto Alomar in 1988, Tatis will be flanked by one of the sport's most experienced infields. Machado will play third, with Ian Kinsler at second and Eric Hosmer at first. That trio has combined for eight Gold Glove Awards.

A side effect of Tatis' presence with the Padres is that close friend and fellow top prospect Luis Urias is expected to begin the season at Triple-A, sources confirmed. Urias is the presumed second baseman of the future, but he was expected to open the year at short -- at least until Tatis' arrival.

That arrival came sooner than most anticipated. And it signaled one thing very clearly: The Padres think their bright future becomes the present on Thursday.