Mitch Keller has agreed to a five-year, $77 million contract extension with the Pittsburgh Pirates, according to sources.

The new deal begins this season and runs through 2028. It buys out the first three years Keller would have been eligible for free agency, paying the pitcher $16.5 million, $18 million and $20 million in those seasons.

Keller, 27, had a breakout 2023 season in which he was an All-Star for the first time and struck out 210 in a career-high 194 1/3 innings.