Sources told MLB.com and USA Today that the Mariners and Phillies have agreed to make the deal, which also involves shortstop prospect J.P. Crawford and other players going to the Mariners. Sources told MLB.com that Carlos Santana is also headed to Seattle in the deal.
Segura must waive his no-trade clause and players must complete physicals before the deal can be finalized.
Segura, 28, hit .304 with 10 home runs and 63 RBIs this season, en route to his second All-Star selection. He owns a career .287 batting average with 64 long balls in his seven seasons. Segura led the National League with 637 at-bats and 203 hits in 2016 while playing for the Arizona Diamondbacks.
He was traded to Seattle in 2016. Segura is under contract through 2022 and has a team option in 2023. He is due $14.8 million in 2019.