De Los Santos (2-1) allowed four runs on two hits and two walks without recording an out to take the loss Tuesday versus the Red Sox.
De Los Santos also took a blown save for failing to protect a 2-1 lead in the eighth inning. It was easily his worst outing of the season -- he had a 6.2-inning scoreless streak from May 19 to June 3 and hadn't given up multiple runs in any appearance since April 9. The right-handed reliever still has a 3.52 ERA with a 1.13 WHIP, 18:10 K:BB and four holds over 23 innings this season. De Los Santos is likely to remain in a middle-reliever role.