The person spoke to The Associated Press on condition of anonymity on Saturday night because no one was authorized to talk about the deal before it was officially announced.
ESPN.com first reported the agreement.
Cobb capitalized on a career year when he had 91 catches for 1,287 yards and 12 touchdowns. He joined Jordy Nelson to become a potent receiving tandem during quarterback Aaron Rodgers' MVP campaign.
The 5-foot-10 Cobb also proved to be an elusive threat in the red zone and over the middle on third downs.
With Cobb returning, the Packers' next top priority might be re-signing right tackle Bryan Bulaga.