CHICAGO (AP) The Chicago Cubs expect starter John Lackey to return from a strained right shoulder this weekend.

Lackey - 9-7 with a 3.41 ERA - threw on Thursday. The team says the session went well, and assuming no setbacks, the veteran will start against San Francisco on Sunday.

Reliever Hector Rondon (strained right triceps) will begin a rehab assignment with Triple-A Iowa on Saturday.

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Reliever Pedro Strop (torn meniscus in left knee) tweaked his right groin in a workout on Wednesday. The Cubs expect him to miss about six weeks after initially projecting him to be out four to six following his injury on Aug. 10.

Chicago activated outfielder Chris Coghlan (ribs) and right-hander Joe Smith (hamstring) from the disabled list and called up righty Jake Buchanan from Iowa.