Cubs' reliever Pedro Strop out 4-6 weeks with knee injury

Chicago Cubs relief pitcher Pedro Strop, left, reacts after injury and third baseman Javier Baez stands behind him during the eighth inning of a baseball game against the Los Angeles Angels in Chicago, Wednesday, Aug. 10, 2016. Strop left the game. (AP Photo/Nam Y. Huh)
Nam Y. Huh/AP

CHICAGO (AP) Chicago Cubs reliever Pedro Strop needs arthroscopic surgery on his left knee and will be sidelined four to six weeks.

The Cubs announced Thursday that an MRI revealed a meniscus tear. Strop was injured fielding a grounder in the eighth inning of Wednesday's victory over the Los Angeles Angels. He was placed on the 15-day disabled list.

The timetable would make it possible for Strop to return before the end of the regular season and be available for the postseason.

The NL Central-leading Cubs had planned to use Strop and Hector Rondon as setup men for closer Aroldis Chapman, who was acquired last month.

The 31-year-old Strop has a 2.89 ERA in 50 games with Chicago this season.

The Cubs recalled right-hander Justin Grimm from Triple-A Iowa.