T.J. Watt recently underwent arthroscopic knee surgery that is expected to delay his return to the Steelers, sources told ESPN.

Watt, who already was recovering from a torn pectoral muscle, had the knee surgery to clean up a preseason injury that lingered into the regular season. The pass-rusher initially was expected to miss six weeks because of the pectoral injury suffered in Pittsburgh's opener, setting up a potential return Oct. 30 against the Eagles.

But the knee surgery likely will push back Watt's return by at least another week or two, according to sources.