Major League Baseball announced Friday it has disciplined umpire Pat Hoberg for violating the league's gambling rules, 10 days after the league levied a lifetime ban on a player for gambling and suspended four others for one year.

Hoberg is appealing the discipline and, according to ESPN sources, has denied betting on baseball. The exact nature of the discipline is unknown, but Hoberg has not umpired a game this season. The league, in a statement, did not indicate whether its investigation into Hoberg showed that he bet on baseball.

In the statement, MLB said: "During this year's Spring Training, Major League Baseball commenced an investigation regarding a potential violation of MLB's sports betting policies by Umpire Pat Hoberg. Mr. Hoberg was removed from the field during the pendency of that investigation. While MLB's investigation did not find any evidence that games worked by Mr. Hoberg were compromised or manipulated in any way, MLB determined that discipline was warranted. Mr. Hoberg has chosen to appeal that determination. Therefore, we cannot comment further until the appeal process is concluded."

Messages left for Hoberg by ESPN earlier this week went unreturned.

Hoberg, in a statement, said: "I am appealing Major League Baseball's determination that I should be disciplined for violating the sports betting policies. While that appeal is pending, it would not be appropriate to discuss the case. That said, I have devoted my adult life to the profession of umpiring, and the integrity of baseball is of the utmost importance to me. I look forward to the appeal process, and I am grateful that the Major League Baseball Umpires Association is supporting me in the appeal.''

If he were found to have bet on baseball, Hoberg would be in violation of MLB's Rule 21, which punishes those who gambled on games in which they were involved with a lifetime ban and games in which they weren't with a yearlong suspension.

The last major American professional sports official known to bet on games was NBA referee Tim Donaghy, who in 2007 was sentenced to 15 months in federal prison after pleading guilty to conspiracy to engage in wire fraud and transmitting betting information through interstate commerce after admitting that he bet on games over four seasons and passed along tips to gamblers.

Hoberg, 37, is best known for his perfect performance in Game 2 of the World Series, when he was home-plate umpire and called all 129 balls and strikes correctly. He is widely regarded as the best ball-strike umpire in MLB.

Hoberg first umpired major league games in 2014 and became a full-time umpire in 2017. Hoberg umpired postseason games every year from 2018-2022 and was assigned to pool games in the 2023 World Baseball Classic.

MLB on June 4 week banned San Diego Padres infielder Tucupita Marcano after a legal sportsbook informed the league that he had bet on games while a member of the Pittsburgh Pirates. Marcano, 24, became the first active player in a century to receive a lifetime ban after he placed more than $150,000 worth of bets in October 2022 and from July to November 2023, according to MLB.

Oakland A's reliever Michael Kelly and three minor league players - Arizona reliever Andrew Saalfrank, Padres starter Jay Groome and Philadelphia infielder Jose Rodriguez - were suspended for a season for betting on major league games while in the minors. Each wagered less than $1,000.

The league investigated and cleared Los Angeles Dodgers star Shohei Ohtani after his interpreter, Ippei Mizuhara, was accused of stealing more than $16 million from Ohtani to cover sports-gambling losses. Mizuhara pleaded guilty June 4 to bank and tax-fraud charges that carry a maximum prison sentence of 33 years.

Additionally, Ohtani's former Los Angeles Angels teammate David Fletcher is under investigation by MLB for allegations that he gambled with an illegal bookmaker, sources told ESPN's T.J. Quinn.

"The strict enforcement of Major League Baseball's rules and policies governing gambling conduct is a critical component of upholding our most important priority: protecting the integrity of our games for the fans," baseball Commissioner Rob Manfred said in a statement announcing the players' discipline. "The longstanding prohibition against betting on Major League Baseball games by those in the sport has been a bedrock principle for over a century. We have been clear that the privilege of playing in baseball comes with a responsibility to refrain from engaging in certain types of behavior that are legal for other people."