The Arizona Cardinals are waiting to hear how long they will be without wide receiver John “Smokey” Brown.

Brown was placed in concussion protocol on Monday after suffering a injury to his head during Sunday’s practice, announced team writer Darren Urban.

He will have to pass the required exams before he is allowed to return to practice. Barring a severe injury, Brown should be able to rejoin the team before the season kicks off on Sept. 11 against the New England Patriots.

The 26-year-old had 1,003 yards on 65 catches with seven touchdowns last season.

Veteran guard Evan Mathis also sat out of Monday’s practice with leg fatigue.

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