[5] After graduation, he served as an intern with the Philadelphia Phillies before joining the front office of the Los Angeles Dodgers, and also worked for Major League Baseball.
His hiring concluded a six-week process that commenced on June 22 after San Diego dismissed Josh Byrnes following a two-plus year tenure, with Preller agreeing to a five-year deal.
He partook in a three team trade for Wil Myers and Ryan Hanigan, surrendering five players (including Trea Turner) in the process.
On September 15, 2016, Preller was suspended for 30 days by MLB without pay for failing to disclose medical information, regarding the trade that sent Drew Pomeranz to the Red Sox.
[11] On February 19, 2018, the Padres signed Eric Hosmer to an eight-year, $144 million contract, the largest in club history at the time.
[16] On August 2, 2022, Preller completed a blockbuster trade with the Washington Nationals for Right fielder Juan Soto and First baseman Josh Bell.
In exchange, the Nationals received Luke Voit and top prospects CJ Abrams, MacKenzie Gore, James Wood, and Jarlin Susana.
On December 9, 2022, Preller signed longtime Boston Red Sox Shortstop Xander Bogaerts to an 11-year 280 million contract.
The TV deal fallout paired with ownership uncertainty resulted in the Padres deciding to shed financial commitments in the 2023-24 offseason.
Ultimately, Preller traded Soto and Trent Grisham to the New York Yankees in exchange for Michael King, Drew Thorpe, Randy Vásquez, Jhony Brito, and Kyle Higashioka.