The Seattle Mariners have finalized an extension with their star rookie centerfielder Julio Rodriguez, the team announced on Friday.

The deal will be worth as much as $470 million in total, with $210 million guaranteed money, according to ESPN, making it the most expensive in MLB history. The base part of Rodriguez will be $120 million and until through the 2029 season. After the 2028 season, the Mainers hold the option to extend it for another eight or 10 years, depending on his performance in the Most Valuable Player (MVP) voting.

If Rodriguez accepts the extension after 2029, his pay will range between $350 million for 10 years at maximum to $200 million for eight years. He can also decline to extend. In that case, the Mariners will need to choose between exercising a five-year, $90 million extension after the 2029 season or allowing him to become a free agent.

By Thursday, Rodriguez had hit a batting average of .269, an on-base percentage of .328 and a slugging percentage of .471 with 64 runs batted in, 20 home runs and 23 stolen bases in 105 games in his first season for the Mariners in the MLB. He was selected for the All-Star Game as well.

The guaranteed money Rodriguez will receive is the most for all players who have not finished playing a full season in the MLB. It surpassed the contracts of Fernando Tatis Jr. with the San Diego Padres (14-year, $340 million) and Wander Franco with the Tampa Bay Rays ($182 million guaranteed for 11 years).

It won't be easy for Rodriguez to maximize his pay to $470 million in the end. Even if he does it, the record may be soon broken by latecomers. For example, designated hitter and pitcher Shohei Ohtani of the Los Angeles Angels will hit free agency after the 2023 season. Juan Soto, who was traded by the Washington Nationals to the Padres, may become a free agent as well in 2024. Soto rejected a $440-million extension offered by the Nationals.

The Mariners beat the Cleveland Guardians 3-2 at T-Mobile Park in Seattle, Washington on Friday to remain second in the American League (AL) West. They are also ahead of the Baltimore Orioles to compete for the final AL Wild Card Game spot.