Strop underwent an arthroscopic procedure on his left knee Thursday and is expected to miss four-to-six weeks, Mark Gonzales of the Chicago Tribune reports.

EDGE Analysis

Although tests revealed a torn meniscus for Strop, his knee ligaments were found to be intact and it sounds like the Cubs are optimistic they'll have Strop available for the postseason at least. Justin Grimm has been recalled to replace Strop on the active roster, while Joe Smith figures to move up in the bullpen hierarchy to take on more high-leverage work in front of closer Aroldis Chapman.