PHOENIX -- It has been 564 days since Fernando Tatis Jr. last graced a baseball field in a major league game with actual stakes. There are obvious concerns -- given the season-long absence, the steroid-related suspension, the surgeries to both his wrist and shoulder -- about whether he can recapture the superstar level he previously displayed.

Not from Tatis, apparently.

Moments before he would make his highly anticipated debut on Thursday night, the San Diego Padres' shortstop-turned-outfielder was asked about his level of confidence in getting back to who he was. Tatis laughed.

"110 percent," he said.

Tatis, 24, was inserted into the leadoff spot for the Padres' series opener against the division-rival Arizona Diamondbacks from Chase Field in Phoenix, where he was followed, respectively, by Juan Soto, Manny Machado and Xander Bogaerts, making up one of the most devastating foursomes in recent memory. Padres manager Bob Melvin wrote out the lineup and immediately texted it to Tatis.

"You've got the green light," he said. "You're leading off."

Tatis hasn't played since 2021, a season that began with a 14-year, $340 million extension and ended with a third-place finish in National League MVP voting. The events that followed changed the entire trajectory of his blossoming career. It began with a motorcycle accident in December 2021, while Major League Baseball was in an owner-imposed lockout that prevented teams from communicating with their players. Tatis later arrived to spring training with a wrist injury that would keep him out for most of the next five months. As he was nearing a return, Tatis tested positive for an anabolic steroid, Clostebol, triggering an 80-game suspension that kept him out for the remainder of 2022 and the first 20 games of 2023.

Tatis believes he is "more mature" in the wake of all that. Asked what he learned from the experience, Tatis said: "That this world goes around so many different ways. You gotta stay humble every time and just enjoy the moment, be grateful every single time. Just be happy."

Tatis' steroid suspension put him on a path to try to earn back trust with his teammates and his bosses. He agreed to undergo the left shoulder surgery that the Padres had recommended a year earlier and also a second cleanup of his injured left wrist; he maintained more regular contact with the organization in the ensuing months; and he went to work early, returning to San Diego for baseball activities in January and being among the first to report to the team's spring training complex in February. Melvin, who didn't spend much time with Tatis during his first season in 2022, found him "easy to manage."

"You do some soul-searching during those times, and you realize how lucky you are to be a big league player," Melvin said. "And when you come back from something like that, you get humbled a little bit and appreciative. He's been nothing but easy to deal with, easy to manage in spring training, and doing anything he has to do to help his team win. I think all the guys feel that."

Tatis began spring training in an 0-for-16 slump, then had 12 hits in his last 26 at-bats. He then dominated a subsequent stint with the Padres' Triple-A affiliate in El Paso, Texas, hitting .515/.590/1.212 with seven home runs in eight games. The last six of those came in a stretch of three games. The first of those prompted the pitcher who gave it up, Kade McClure, to call him a "cheater" on Twitter, an indication of the backlash Tatis will receive upon his return.

"That's gonna come," Tatis said. "Everybody has freedom of expression in this country, and nothing I can do about it. I'm just gonna keep playing this game and enjoy every part of it."

Tatis has undoubtedly seemed joyful as he has made his way back to baseball. He has smiled often, has approached his new position of right field with noticeable enthusiasm -- the type he didn't display when forced to occasionally play there in order to account for frequent shoulder subluxations -- and has celebrated with his customary flair and swagger.

"Just being far for a period of time, it gave me time to realize how really blessed I am to be able to play this game at the level that I play it," Tatis said. "All the kids that are watching, the vibe they give me, that love they give me, it just feeds me every single time."

Before the events of 2022, Tatis was looked upon as the next face of his sport, securing major sponsorship deals with Adidas and Gatorade and gracing the cover of the popular video game "MLB: The Show." By that point, he had become the first player to combine at least 80 home runs and 50 stolen bases within his first 300 career games. Tatis totaled 81 home runs and 52 stolen bases in 273 career games, all before his 23rd birthday.

He still thinks that's who he is.

"It's just me playing baseball," Tatis said. "It's nothing different. It's been the same way since Day 0, and it's gonna keep being the same way."