The Seattle Mariners and first-base prospect Evan White have agreed to a six-year, $24 million contract with three club options, sources familiar with the deal confirmed to ESPN's Jeff Passan on Friday.

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.

In 2018, the Philadelphia Phillies signed Scott Kingery, who had played a full season at the Triple-A level, to a six-year, $24 million deal that could max out at $42 million combined.

White's deal with the Mariners can max out in the mid-$50 million range, sources told Passan. Barring a disastrous spring training, White is expected to be Seattle's first baseman on Opening Day.

MLB.com was the first to report White's agreement with the Mariners.

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.