The Denver Broncos placed wide receiver Clifford Russell on the reserve-injured list Tuesday and signed free-agent wide receiver Glenn Martinez.
Russell suffered a sprained neck on kickoff coverage in the fourth quarter of the Broncos' 33-19 loss at Kansas City on Sunday.
Russell, a sixth-year pro who had signed with the Broncos on Sept. 17, saw a neurosurgeon on Monday but no details were released.
Martinez is a third-year pro who played for the Broncos last season but was waived on Aug. 30.
He appeared in 12 games with one start last year. He had 14 receptions for 175 yards, 15 kickoff returns for 330 yards and 14 punt returns for 157 yards and a touchdown.