The Seattle Mariners signed first-base prospect Evan White to a six-year major league contract with three club options, the team announced Monday.
Financial terms were not disclosed, but sources familiar with the deal confirmed to ESPN's Jeff Passan that the deal is worth $24 million.
White, 23, spent all of last season at Double-A with the Arkansas Travelers of the Texas League. No player at that level has ever received a long-term extension.
White's deal with the Mariners can max out in the mid-$50 million range, sources told Passan.
"Evan White stands out in so many ways," Mariners general manager Jerry Dipoto said in a statement. "We love the player and we love the person. The combination made it very easy to want to sign him for the better part of the next decade.
"We believe this is the next stage in a long-term investment in our young players, in bringing together young, core players who have a ton of talent and are also high-character people."
Barring a disastrous spring training, White is expected to be Seattle's first baseman on Opening Day. The Mariners used eight players at the position last season, with Austin Nola and Daniel Vogelbach getting most of the playing time there.
In 2018, the Philadelphia Phillies signed Scott Kingery, who had played a full season at Triple-A, to a six-year, $24 million deal that could max out at $42 million combined. Eloy Jimenez of the Chicago White Sox also signed a long-term deal in Triple-A before making it to the majors.
The Mariners see White as a major part of their future core, along with fellow top prospects Jarred Kelenic, Kyle Lewis, Logan Gilbert, Justin Dunn and Justus Sheffield.
A non-roster invitee to spring training last year, White had a .293 batting average with 18 home runs and 55 RBIs in 92 games while being named to the Futures Game last season.
White, the 17th overall pick in the 2017 draft out of Kentucky, also was a Double-A All-Star selection by Baseball America.
In three minor league seasons, White has a .296 batting average with 32 home runs and 133 RBIs.
The Associated Press contributed to this report.