The Seattle Mariners are locking up their young star, finalizing a long-term extension with rookie Julio Rodriguez on Friday.

The deal, which has not been confirmed by the Mariners organization, will guarantee Rodriguez $210 million over 14 years and could exceed $400 million by the end of the pact, according to ESPN.

In his rookie season, Rodriguez is having a breakout year, hitting .269/.328/.471, with 20 home runs, 64 RBI and 23 stolen bases. He is the first Mariners rookie to hit 20 home runs and steal 20 bases in a single season, and he was selected to his first All-Star Game.