In the start of 2019, MLB Pipeline, ESPN, Baseball America, and Baseball Prospectus all listed Tatís among the top three baseball prospects.[16][17][18] Tatís was added to the Padres Opening Day roster, the team announced on March 26, 2019.[19] He had two hits in his major league debut against the San Francisco Giants.[20] Tatís hit his first major league home run on April 1, 2019.[21]
Tatís suffered a back injury in August, which caused his 2019 season to stop.[22] He hit towards the end of the season.317/.379/.590 over 84 games with 61 runs, 106 hits, and 22 home homers.[23] After Mike Soroka and Pete Alonso, he finished third in the voting for the National League Rookie of the Year Award.[24]
Tatís participated in a four-game stretch in August of the 2020 season during which the San Diego Padres hit four grand homers. Notably, he was at every base position during the four games.[25] When Tatís hit an opposite-field grand slam against the Texas Rangers in the eighth inning after swinging at a 3–0 pitch, there was a stir. Since the Padres were ahead by seven runs at the time, there was some debate about breaching a “unwritten rule of baseball” in this situation.[26]
Prior to the 2021 season, Tatís committed to a 14-year, $340 million contract extension with the Padres. This was the wealthiest deal ever signed by a player who was not yet eligible for salary arbitration, and it was the third-richest in MLB history, behind only Mike Trout and Mookie Betts’ deals.[31] An arrangement Tatís negotiated while in the minor leagues to obtain early money to “afford a personal trainer, higher quality food and better housing” calls for giving Big League Advance a portion of Tatís’s future profits.[32]
Tatís blasted two home runs off Clayton Kershaw on April 23, exactly 22 years after his father hit two grand slams in one inning. He also hit two more home runs off Trevor Bauer in a different game. At the same location where Tatís’s father had made history, there were four home runs. The Padres triumphed 6-1.[35]
Tatís and Wil Myers, two San Diego Padres players, tested positive for COVID-19 on May 12. As a result, Tatís was placed on the injured list.[36] The Padres activated Tatís off the COVID-19 IL on May 19.[37]
