Source: Josh Sitton goes to Chicago for 3 years, $21.5M

CHICAGO -- The Bears have reached an agreement on a three-year contract with former Green Bay Packers guard Josh Sitton.

ESPN NFL Insider Adam Schefter reports Sitton's new deal is worth $21.5 million and includes $10 million in guarantees.

The Packers released Sitton, a three-time Pro Bowl left guard, after being unable to trade him.

"We want to thank Josh for his contributions during his time in Green Bay. He has been an important part of the success we have enjoyed on the field," Packers general manager Ted Thompson said.

"While these decisions are never easy, this was done with a focus on what is best for the team and the growth of the offensive line. We wish Josh and his wife, Kristen, all the best in the future."

Sitton, 30, has started 110 of 112 Packers regular-season games since the beginning of the 2009 season.

"First of all, the skins are on the wall, three-time Pro Bowler, he's extremely strong and powerful in the run game, and pass pro, he's one of those guys that just makes it look easy," said Bears GM Ryan Pace on why the team moved quickly to sign Sitton. "You never see him stressed or exposed. He's in good position, smart, very intelligent player and that shows up when you meet with him and all the research we did on him echoed that as well."

Sitton's arrival shakes up the Bears offensive line. Rookie Cody Whitehair started at left guard the entire preseason, but the 2016 second-round pick has practiced some at center. Veteran Ted Larsen assumed the starting center positon when Chicago lost Hroniss Grasu to a season-ending torn ACL.

On Saturday, the Bears agreed to a four-year extension with right guard Kyle Long, who is pushing to return from shoulder injury in time for Chicago's Week 1 game at Houston.

ESPN's Rob Demovsky contributed to this report.