279 innings pitched. Boston Red Sox On December 7, 2015, the Mariners traded Elías and Carson Smith to the Boston Red Sox for Wade Miley and Jonathan Aro. Elías made his Boston debut in relief on April 23, 2016, against the Houston Astros. In June, he was called up from the Triple-A Pawtucket Red Sox and faced his former teammates in his first starting appearance with the Red Sox on June 17, giving up seven runs over four innings. Elías was optioned back to Pawtucket after the game. He made one additional appearance for Boston during the season, pitching two innings of one-run relief against the Arizona Diamondbacks on August 16. Overall, for the 2016 season, Elías made three appearances for Boston, pitching innings with a 12.91 ERA and 0–1 record. Elías started the 2017 season on the disabled list, due to a muscle strain suffered in early March. After missing several months of the season, he played with four different Red Sox farm teams; the Single-A Lowell Spinners and Salem Red Sox, Double-A Portland Sea Dogs, and Triple-A Pawtucket. For those four teams, he pitched a total of innings in 10 games with a 6.96 ERA and a 1–6 record. Late in the season, he made a single appearance for Boston, pitching of an inning on September 4 against the Toronto Blue Jays; he walked one batter and struck out one batter. Elías started the 2018 season with Triple-A Pawtucket, where he appeared in four games in relief, pitching a total of innings with a 1.23 ERA, 1–0 record, and one save. Overall for the Red Sox, Elías appeared in 4 MLB games (one start) with a 0–1 record with 12.38 ERA in 8 innings pitched. Second stint with Mariners On April 23, 2018, the Red Sox traded Elías to the Seattle Mariners for a player to be named later (PTNBL) or cash considerations. They agreed on Eric Filia as the PTBNL in June, but Filia failed his physical exam with the Red Sox, and was returned to Seattle, with the Red Sox acquiring cash considerations instead. After reporting to Triple-A Tacoma, he went 2–4 with a 4.94 ERA (17 ER, 31.0 IP) with 27 strikeouts and 12 walks in 7 games (6 starts). On June 1, 2018, Elías was called up from Tacoma to make his season debut against the Tampa Bay Rays, in which he tossed two