TEMPE, Ariz. -- It took just two months into Tyrann Mathieu's rookie season for an award to come his way, as the Arizona Cardinals safety was named the NFC's defensive rookie of the month for October on Thursday.

Cardinals safety Tyrann Mathieu was named the NFC's defensive rookie of the month for October, when he had 21 tackles, five passes defensed, one interception and one sack in four games. AP Photo/Ric Tapia

Mathieu had 21 tackles, five passes defensed, one interception and one sack in October, capping the month with a pick of Atlanta Falcons quarterback Matt Ryan to complement his seven tackles in the Cardinals' 27-13 win.

Mathieu is the first safety to win the award since Kansas City's Eric Berry in December 2010, according to Randall Liu, the NFL's director of NFC communications.

The rookie also recorded his first sack in October, bringing down Carolina Panthers quarterback Cam Newton in Week 5. For the season, Mathieu is second on the Cardinals with 47 tackles. He also has two interceptions.

Mathieu has started six of Arizona's eight games and became a regular starter in Week 4 against the Tampa Bay Buccaneers. He was in the starting lineup for all four games in October.

Mathieu became the third Cardinal to win the award, joining Dominique Rodgers-Cromartie in December 2008 and Simeon Rice in September 1996.

Mathieu, the erstwhile "Honey Badger" and a Heisman Trophy finalist in 2011, dropped to the third round in April's NFL draft after missing last football season following a dismissal from LSU in August 2012 for failed drug tests.