The 27-year-old Elias, who has yet to make his Red Sox debut, will be in the Majors for the first time this season. Elias spent the 2014 and '15 seasons with the Mariners, going 5-8 with a 4.14 ERA in 22 games (20 starts) a year ago. He has made two starts for Pawtucket in 2016, posting a 3.86 ERA in 9 1/3 innings.
Cuevas made one relief appearance for the Red Sox this season, allowing two runs in 2 1/3 innings and taking the loss in his Major League debut.
David Adler is a reporter for MLB.com. Follow him on Twitter @_dadler. This story was not subject to the approval of Major League Baseball or its clubs.