Chris Martin’s absence was noticeable on Thursday, when the Red Sox needed 12 innings and five relievers to complete their sweep of the Marlins in Miami.

Before Friday night’s series opener against the Yankees, manager Alex Cora explained why: Martin has been placed on the 15-day injured list with “right-elbow inflammation.”

“We’ll know more over the course of the weekend,” Cora told reporters at Yankee Stadium. “He didn’t feel great after the last one. Kind of felt sluggish and felt some pain. We feel like this is something minor, but obviously where we’re at in the season with the day off on Monday and the All-Star Break, it doesn’t make sense to push him out there and we lose him for a longer period of time, so that’s the move.”

Though elbow issues are always a cause for concern, Cora said he doesn’t think the injury is serious. There’s no imaging scheduled at present.

“He tried to play catch today,” the Sox skipper said. “It started off well but then after that, he felt tightness, so we’re going to shut him down. … If he has to go to Boston (to get checked out), he’ll go to Boston.”

Martin has been key to Boston’s success; he owns a 3.42 ERA over 26 games, with 29 strikeouts and just two walks over 26.1 innings, and the Red Sox are 18-8 when he pitches. However, it’s been a difficult season for the Red Sox setup man; Friday marks one month since the club placed the right-hander, 38, on the 15-day IL due to anxiety. Since being activated on June 19, he’d looked like his usual lock-down self, making five scoreless appearances with four hits, zero walks, and five strikeouts.

To fill Martin’s spot on the active roster, the Red Sox have recalled left-hander Cam Booser from Triple-A Worcester.