Fernando Tatis Jr has signed a 14-year contract with the San Diego Padres, the longest deal in Major League Baseball history.
The 22-year-old's deal is worth $US340 million ($A430 million).
"Fernando is a special talent who will be instrumental in bringing a world championship to the city of San Diego," general manager AJ Preller said in a statement.
"Throughout the process, Fernando's desire to stay here long term was clear, and we are thrilled that we were able to come to an agreement."
Tatis had been eligible for salary arbitration after this season and for free agency after the 2024 season.
The length of his contract exceeded the 13-year agreement in November 2014 between Miami and Giancarlo Stanton, who was traded to the New York Yankees in December 2017, and 13-year contract ahead of the 2019 season between Bruce Harper and Philadelphia.
Baseball's biggest deal by dollars remains Mike Trout's $US426.5 million ($A539.0 million), 12-year contract signed with the Angels in March 2019.
Tatis' deal is the third-largest, also trailing Mookie Betts' $US365 million, 12-year contract with the Los Angeles Dodgers that starts this season.
A son of former major leaguer Fernando Tatis, he has a .301 average in 143 career big league games with 39 home runs and 98 RBIs since his debut in March 2019.