The San Francisco 49ers' weakest unit, their offensive line, got a little worse today. G Alex Boone will be signing with the Minnesota Vikings once free agency kicks off at 1 PM (PT) today, per Adam Schefter of ESPN.


NFL Network's Ian Rapport reports that Boone was the Vikings guard of choice after former Baltimore Raven Kelechi Osemele. Osemele will sign a lucrative deal with the Oakland Raiders.

Boone is one of four remaining 49ers unrestricted free agents. The others are WR Anquan Boldin, RB Reggie Bush, and K Phil Dawson.

Seeking a new contract, Boone held out of the 49ers' 2014 training camp. He was recently rated by Pro Football Focus as the fifth best guard available in free agency. Boone was signed as an undrafted free agent out of Ohio State in 2009. He has been selected to two Pro Bowls (2013, 2015).