Alex Boone signs with Vikings, ending whirlwind tenure in San Francisco

Goessling: Boone adds toughness to Vikings (2:47)

ESPN Vikings reporter Ben Goessling explains why Alex Boone is a perfect fit for the Vikings and their fans. (2:47)

MINNEAPOLIS -- The Minnesota Vikings addressed one of their biggest needs by reuniting new offensive line coach Tony Sparano with a player from his recent past.

The team will sign former San Francisco 49ers guard Alex Boone when the new league year begins Wednesday afternoon, a source told ESPN NFL Insider Adam Schefter.

Boone, who played for Sparano in San Francisco last year, should help an offensive line that struggled to protect Teddy Bridgewater the past two years.

The 6-foot-8, 300-pound Boone, who turns 29 on May 4, held out the past two offseasons but started all but one game he played for the 49ers in the past four seasons (59 of 60). He moved from right guard to left guard last season, despite a seeming desire to move out to right tackle.

Boone, who missed the Niners' season finale when he was placed on injured reserve with a right knee injury, is outspoken, criticizing the refs after a close loss to the Arizona Cardinals at home in Week 12 last season. He once defended then-coach Jim Harbaugh by calling him a "brother" to local media before an about-face in the 2015 offseason for HBO's cameras, saying he wanted to fight Harbaugh because he drove the team too hard.

Boone spent seven years with the 49ers, including a year on the practice squad. An endangered black rhinoceros at the San Francisco Zoo was named after him in January 2013.

ESPN 49ers reporter Paul Gutierrez contributed to this report.