MANKATO (AP) — The Minnesota Vikings have locked up another core piece of their defense, agreeing to a contract extension with nose tackle Linval Joseph.

Joseph’s agency, SportsTrust Advisors, announced the deal Saturday. NFL Media reported it’s a four-year extension worth as much as $50 million with $31.5 million in guaranteed money. This is the third extension the Vikings have done since training camp began, having previously signed defensive end Everson Griffen and cornerback Xavier Rhodes to new long-term deals.

This is Joseph’s fourth season with the Vikings, all under coach Mike Zimmer, who recently called Joseph the best nose tackle he’s “ever been around.” The 6-foot-4, 329-pound Joseph was picked as an injury replacement last year for the Pro Bowl.