We now know why the Boston Red Sox acquired Brad Ziegler during the late hours on Friday evening. Just hours after making that move, the team place closer Craig Kimbrel on the 15-day disabled list with a meniscus tear in his left knee. 

The prognosis for recovery for Kimbrel could be as much as six weeks. But depending on the severity of the tear, he could be back in less than a month. Kimbrel's first season in Boston hasn't been incredibly great. While he's still posting an elite-level 1.09 WHIP, his 3.55 ERA is the worst of his career. Still, this hasn't kept the closer from earning an All-Star nod, which he obviously won't take part in now. 

Ziegler will take over as Boston's primary closer with Kimbrel out. He tallied 30 saves with a 1.85 ERA for Arizona last season.