The player to be named later acquired from Seattle in exchange for pitcher Roenis Elias was indeed named on Tuesday, as the Mariners sent minor league outfielder Eric Filia to the Red Sox.
The 25-year-old Filia has spent his entire 2018 season with Double-A Arkansas, where he's delivered hits in 23 of his 54 at-bats, good for a .426 average with one home run and 14 RBIs. Filia, who bats lefty and throws righty, was a 20th round pick of the Mariners back in 2016.
Filia was ranked as the 21st-best prospect in the Seattle system.
The Red Sox traded Elias to the Mariners on Apr. 23. He has since posted a 1-0 record and 1.50 ERA in six innings of work over two appearances for the M's. Elias was originally obtained by the Sox from the Mariners in Dec. 2015.