San Diego Padres shortstop Fernando Tatis Jr. has been suspended for 80 games after testing positive for Clostebol, a performance-enhancing substance in violation of Major League Baseball's Joint Drug Prevention and Treatment Program.

Tatis' suspension, announced by MLB on Friday, is effective immediately, meaning the All-Star shortstop cannot play in the majors this year. In a statement, Tatis said he is not appealing the ban as it was his "mistake" that led to the positive test.

"It turns out that I inadvertently took a medication to treat ringworm that contained Clostebol," Tatis said. "I should have used the resources available to me in order to ensure that no banned substances were in what I took. I failed to do so.

"I want to apologize to Peter [Seidler], AJ [Preller], the entire Padres organization, my teammates, Major League Baseball, and fans everywhere for my mistake. I have no excuse for my error, and I would never do anything to cheat or disrespect this game I love. I have taken countless drug tests throughout my professional career, including on March 29, 2022, all of which have returned negative results until this test.

"I am completely devastated. There is nowhere else in the world I would rather be than on the field competing with my teammates. After initially appealing the suspension, I have realized that my mistake was the cause of this result, and for that reason I have decided to start serving my suspension immediately. I look forward to rejoining my teammates on the field in 2023."

Tatis was on a minor league rehabilitation assignment after missing the first four months of the season because of a broken left wrist and will now be on the restricted list for the final 48 games of the Padres' regular season. Any postseason games the Padres play this season will count toward Tatis' 80-game total. The remainder of the suspension will be served at the beginning of the 2023 season.

Freddy Galvis and Dee Gordon are among the major leaguers previously suspended for using Clostebol, an anabolic steroid that can be used for ophthalmological and dermatological use. It is also banned by the World Anti-Doping Agency, and Olympic gold-medal-winning cross-country skier Therese Johaug was suspended in 2016 after testing positive for it.

MLB said the suspension also will knock Tatis out of playing for the Dominican Republic in the World Baseball Classic.

Tatis, 23, is one of the biggest stars in MLB, the centerpiece of multiple marketing campaigns and in the second season of a 14-year, $340 million contract.

After emerging as a star in his rookie season at 20, Tatis, a 6-foot-3, 220-pound shortstop whose power, speed and penchant for the spectacular won him legions of fans, finished fourth in the National League MVP voting in his sophomore campaign. Last year, he was even better, signing the record deal, finishing third in MVP voting and solidifying himself as one of the game's finest players.

The Padres collapsed down the stretch but held high hopes for 2022 after hiring Bob Melvin as their new manager. During the lockout that delayed spring training, Tatis fractured his wrist in a motorcycle accident that required surgery. San Diego vowed to take his rehabilitation slowly and was teeming with anticipation of a lineup with Tatis leading off, new acquisition Juan Soto hitting second and third baseman Manny Machado third.

The penalty was announced shortly before the Padres played at Washington. San Diego began the day at 63-51 and held the final of the three NL wild-card spots.

"We were surprised and extremely disappointed to learn today that Fernando Tatis Jr. tested positive for a performance-enhancing substance in violation of Major League Baseball's Joint Prevention and Treatment Program and subsequently received an 80-game suspension without pay," the Padres said in a statement. "We fully support the program and are hopeful that Fernando will learn from this experience.''

The suspension will cost Tatis about $2.9 million. Tatis will forfeit $1,510,989 of his $5 million salary this year, covering the final 55 days and 48 games of the season. He will lose approximately $1.39 million of his $7 million salary for the first 32 games of next season, with the exact number to be determined by how many days he misses.

In 273 career games, Tatis is hitting .292/.369/.569 with 81 home runs, 192 RBIs and 52 stolen bases.

The Associated Press contributed to this story.