CHICAGO -- The overhaul of the Bears' offensive line began just over a week before the start of the NFL's free agency period. The Bears are in the process of sending a 2025 sixth-round pick to the Los Angeles Rams in exchange for guard Jonah Jackson, multiple sources told ESPN.

The trade cannot be processed until the start of the new league year on March 12.

Jackson, 28, has started 61 games over five NFL seasons, which included a Pro Bowl campaign in 2021. He has predominantly played at left guard since being drafted by the Detroit Lions, where he played for new Bears coach Ben Johnson for four seasons.

Jackson, who signed a three-year, $51 million contract with the Rams in March 2024, is scheduled to make $17.5 million in salary during the 2025 season. Chicago is taking on the entirety of Jackson's salary as part of the trade, a source told ESPN's Adam Schefter.

A shoulder injury limited Jackson to four games last season where he took snaps at left guard, center and right guard. He missed most of training camp after sustaining the injury in late July and returned for the start of the regular season before aggravating his shoulder in Week 2 and landing on injured reserve. Jackson played in one game after returning from IR and then was benched.

In his end-of-season news conference, Rams head coach Sean McVay said he really appreciated how professionally Jackson handled his 2024 season in Los Angeles.

"I really appreciate Jonah on how he handled [the situation]," McVay said in January. "A starting-level player ... there are a lot of teams that would love to have Jonah Jackson at guard. ... He put the team first in terms of just showing up, going to work and being a really good 'scout teamer.'"

Chicago's offensive line is a major area of focus this offseason with three primary starters -- left guard Teven Jenkins, center Coleman Shelton and right guard Matt Pryor -- set to hit free agency. Quarterback Caleb Williams was sacked a league-high 68 times during his rookie season, which has prompted a push for the Bears to address multiple needs up front.

Last week at the NFL combine, Johnson addressed the possibility that the Bears could flip the entire interior of the offensive line in one offseason.

"Yeah, I think it's been done before, right?" Johnson said. "I mean, there are a number of teams that did that last year. The Panthers come to mind when they went out in free agency and got a couple of top guards, really changed the dynamic of their offense. You saw them clicking there in the second half of the season once they really started to gel. There's no question that you can change the dynamic of the room just like that. That particular room, it does take time for five guys to come together. Especially if you have to deal with attrition and injuries for five guys to be working on the same page."

Jackson was given permission to seek a trade last week, a source confirmed to ESPN. Prior to joining the Rams last offseason, Jackson logged 57 starts for Detroit from 2020-23.

ESPN's Sarah Barshop contributed to this story.