The outside linebacker is done for the season, the third injury at the position for the team stemming from last Sunday's loss at New Orleans.
The Cardinals elevated linebacker Kenny Demens from the practice squad.
Okafor, a fourth-round draft pick out of Texas, said in a tweet on Tuesday that he would be back next year ''stronger than ever.''
The Cardinals are practicing in Bradenton this week in preparation for Sunday's game against Tampa Bay.
AP NFL website: www.pro32.ap.org
- Sports & Recreation
- American Football
- Arizona Cardinals
- Alex Okafor
- outside linebacker
- Lorenzo Alexander