He was named an All-Star in 2021 and won a second Silver Slugger Award, before missing the 2022 season due to injury and a suspension for using a performance-enhancing substance.

[3] Fernando Jr. held an interest in baseball from a young age, and was athletic and spent a lot of time in big league clubhouses.

[4] The Chicago White Sox signed Tatís as an international free agent from the Dominican Prospect League in 2015.

[5][6] On June 4, 2016, before he had played a professional game, the White Sox traded Tatís, then 17 years old, and Erik Johnson to the Padres for James Shields.

[10] In 2017, Tatís played 117 games for the Fort Wayne TinCaps of the Class A Midwest League and 14 games for the San Antonio Missions of the Class AA Texas League, posting a combined .278 batting average with 22 home runs, 75 RBIs, and 32 stolen bases as he was caught 15 times, and on defense, he made 30 errors and had a .936 fielding percentage.

[11][12][13] In 2017–18, he played 17 games at shortstop for the Estrellas de Oriente of the Dominican Winter League, batting .246 with one home run and three RBIs.

[14] He returned to play shortstop for San Antonio, and in 88 games he batted .286 with 16 home runs, 43 RBIs, and 16 stolen bases.

[10] On July 23, 2018, Tatís underwent season-ending surgery for a broken left thumb and ligament damage suffered during a head-first slide.

[25] In the 2020 season, Tatís was part of a four-game streak in August in which the San Diego Padres hit four grand slams, and, notably, was at each base position over the four.

[26] There was a controversy involving Tatís when he swung at a 3–0 pitch in the eighth inning, hitting an opposite-field grand slam against the Texas Rangers.

[29][30] Tatís finished in fourth place for the National League MVP Award in 2020, behind Freddie Freeman, Mookie Betts, and his teammate Manny Machado.

On April 5, Tatís sustained a left shoulder subluxation while swinging at a pitch during a game against the San Francisco Giants.

[44] Tatís suffered a second left shoulder subluxation while playing against the Colorado Rockies on July 30 and was placed on the 10-day IL.

[50] He won his second consecutive Silver Slugger Award[51] and finished third in NL MVP voting behind Bryce Harper and Juan Soto.

[53] Although the cause of the injury was not confirmed, general manager A. J. Preller alluded to a motorcycle accident that Tatís suffered in December 2021 in the Dominican Republic.

[59] While playing for the Padres' Triple-A affiliate El Paso Chihuahuas, Tatís recorded 17 hits and 15 RBIs in 33 at bats, including a three home run, eight-RBI game on April 13, 2023.

[60][61] With the Padres signing free agent shortstop Xander Bogaerts, Tatis was moved to right field,[62] where he won a Gold Glove after leading all NL defenders with 27 defensive runs saved.

Tatís posted an average sprint speed of 29.3 feet per second through his first three seasons and placed in the 98th percentile of all MLB baserunners in 2020.