The Vikings have made their first significant addition of the 2016 offseason, signing free-agent guard Alex Boone. It is a four-year, $26.8 million contract with $10 million guaranteed, per a league source.

Boone, 28, is a two-time Pro Bowler who played the first six seasons of his career in San Francisco. After going undrafted out of Ohio State in 2009, he played 77 games with the 49ers, starting 59 of them.

The 6-foot-8, 300-pounder has played both guard spots for the 49ers. He played left guard in 2015. He can also play tackle in a pinch.

The Vikings said after the season that they would put a priority on fixing the offensive line after it hamstrung the offense in 2015.

No NFL quarterback was pressured more frequently than Teddy Bridgewater, according to Pro Football Focus. And while the starting fivesome helped Adrian Peterson win his third career rushing title, the Vikings feel Peterson too often had to try to make something out of nothing.

The addition of Boone could mean that the Vikings move Brandon Fusco back from left guard to right guard. It could also mean that right guard Mike Harris could be allowed to walk in free agency. But Boone can't even sign the deal until 3 p.m. today, so let's not get ahead of ourselves.

In other news, the Vikings have agreed to terms with former Lions linebacker Travis Lewis, according to a report from FOX Sports. Lewis started four games for the Lions last year and made 21 tackles, but he will presumably provide depth at the position.