Rookie second baseman Kristian Campbell and the Boston Red Sox agreed to an eight-year extension Wednesday, marking the earliest in a career the Red Sox have ever locked up a player to a multiyear deal.

The extension is worth $60 million, sources told ESPN.

Barely a week into Campbell's time in the big leagues, the Red Sox showed even more faith in Campbell than they had by breaking camp with him. The deal, which will go through the 2034 season, includes two club options, sources told ESPN.

Campbell, 22, was the consensus minor league player of the year in 2024 after a star-making performance that came out of nowhere. With an unorthodox-looking right-handed swing, Campbell hit .330/.439/.558 with 20 home runs and 77 RBIs while jumping from High-A to Triple-A.

Boston officials entered camp hopeful Campbell would earn the second-base job, and despite the possibility of big-dollar free agent signing Alex Bregman occupying it. Bregman remained at third base, with Rafael Devers switching to designated hitter to accommodate Campbell's arrival.

The Red Sox's continued spending -- they locked up ace Garrett Crochet to a six-year, $170 million deal earlier this week -- enriches a long-term core that includes Devers signed until 2033, super-utility man Ceddanne Rafaela through 2031, Crochet and right-hander Brayan Bello through 2030 and the forthcoming arrival of Campbell's running mates in Boston's big three prospects, outfielder Roman Anthony and shortstop Marcelo Mayer.

Boston's desire to lock in players to early-career deals in hope of maximizing their performance is no secret. And Campbell's first week with the Red Sox only serves as validation: He's hitting .375/.500/.688 with a long home run to left-center field.

Campbell's burgeoning power helped launch him toward the top of prospect lists this winter. After hitting .376/.484/.549 in his lone season at Georgia Tech, Campbell went to the Red Sox in the fourth round with the compensation pick they received for losing Xander Bogaerts to San Diego in free agency. Boston coaches helped rebuild Campbell's swing and saw immediate results, more than doubling his homer-per-game output from college.

At 6-foot-3 and 210 pounds, Campbell will be the solution for a second-base position held down for more than a decade by Dustin Pedroia. Since his retirement following the 2017 season, the Red Sox have been led in games played at second by six different players in seven years.