Red Sox manager Alex Cora said Jansen (back) is still being evaluated ahead of Sunday's series finale against the Mariners, and the closer's availability has yet to be determined, Ian Browne of MLB.com reports.

EDGE Analysis

Jansen was unavailable to pitch Saturday due to back tightness, and it remains unclear if he'll be ready to go Sunday. The Red Sox seem likely to be cautious with the 36-year-old early in the season, especially since he had limited reps during spring training due to lat and back issues. Should Jansen be unavailable, Chris Martin is the favorite to fill in should a save chance arise.