MINNEAPOLIS (AP) — A person with direct knowledge of the deal tells The Associated Press the Minnesota Vikings have agreed to a four-year contract with former San Francisco 49ers left guard Alex Boone.

The person spoke Wednesday on condition of anonymity because the team had not yet announced the signing.

The 6-foot-8, 300-pound Boone brings feistiness and experience to an unsettled offensive line, the top offseason need for the Vikings. Boone switched from right to left guard last year, when new Vikings offensive line coach Tony Sparano supervised San Francisco's tight ends.

Boone was on the 49ers practice squad in 2009, made the active roster the following year and became a starter in 2012.

The Vikings also finalized a one-year contract with backup defensive tackle Kenrick Ellis.