Trevor Story and the Boston Red Sox have agreed to a six-year, $140 million contract, sources confirmed to ESPN.

The deal includes an opt-out after the fourth season, sources said.

Story hit a crowded free-agent field -- alongside fellow shortstops Carlos Correa, Marcus Semien, Javier Baez and Corey Seager -- with a résumé featuring two All-Star Games, two Silver Slugger awards and MVP votes during the 2018, 2019 and 2020 seasons.

The concern with any player who built his career with the Colorado Rockies is that career numbers are skewed by playing half of his games at Coors Field. Story's batting average and on-base percentage are 60 points lower on the road, his slugging percentage 160 points lower, and his wRC+ 27 points lower. In recent history, Nolan Arenado, DJ LeMahieu and Troy Tulowitzki all became markedly better road hitters with worse home splits after leaving Colorado, though three players is hardly a definitive sample size.

Story, 29, could be moved to second base alongside Red Sox shortstop Xander Bogaerts. At the major league level, Story has never played a position other than shortstop, where he ranked among the majors' best in 2019 with plus-18 outs above average and was an NL Gold Glove finalist.

Story has shown big power in the past, hitting 37 homers in 2018, 35 in 2019, 11 during the pandemic-shortened 2020 season, and 24 in 2021. In 2019, Story reached 100 career homers in 448 games, becoming the fastest shortstop to ever do so. In his six-year tenure with Colorado, he solidified himself as one of the best players in franchise history, ranking in the top 10 in homers, doubles, triples and stolen bases. He also tied for 14th in the majors in steals last season with 20.

USA Today first reported on the Red Sox's agreement with Story.

ESPN's Joon Lee contributed to this report.