Shocking news in the baseball world ... Fernando Tatis Jr. -- one of the best players in the MLB -- has just been suspended 80 games!
Commissioner Rob Manfred announced the ban on Friday afternoon -- after he and the league say the San Diego Padres' all-world shortstop tested positive Clostebol, a performance-enhancing substance.
According to the MLB, Tatis' suspension will begin immediately.
The Padres, meanwhile, said in a statement that they were "surprised and extremely disappointed" to learn of the positive test.