Vikings extend DE Robison's contract

Defensive end Brian Robison reached agreement on a contract extension with the Minnesota Vikings, the team announced Wednesday.

The four-year, $28 million extension includes $13 million guaranteed, according to reports. Robison is in the final year of a three-year contract he signed in 2011.

The 30-year-old Robison has 10 tackles, one sack and 11 quarterback hurries in four games this year. In the previous two seasons, he totaled 16.5 sacks. The seven-year pro has 31 career sacks.

Vikings defensive end Jared Allen, defensive tackles Kevin Williams and Fred Evans and backup defensive end Everson Griffen remain unsigned past this season. Allen, 32, had 34 sacks the previous two years.