Chicago Bears wide receiver Alshon Jeffery has been given a four-game ban for violating the NFL's performance-enhancing drug policy.
Jeffery signed a one-year extension as the Bears' franchise player for 2016 worth $US14.6 million ($A19.3 million).
His suspension is a huge blow for the battling Bears who are 2-7 and sit bottom of the NFC north conference.
"I think he's fairly embarrassed about it, but we'll support him," Bears coach John Fox said.
"We'll support him and welcome him back after serving his suspension."
The 26-year-old Jeffery leads the Bears with 630 receiving yards and is second on the team with 40 receptions and scored one touchdown.
He is eligible to return against the Green Bay Packers on December 18.
Jeffery will be a free agent this off-season unless the Bears apply their franchise tag on him again.
