A few hours after they announced that quarterback Matthew Stafford would return, the Rams agreed to terms with left tackle Alaric Jackson on a three-year contract, a person with knowledge of the situation said Friday.

The person requested anonymity because the deal has not been completed.

Jackson, who signed with the Rams as an undrafted free agent in 2021, was due to become an unrestricted free agent when the new league year begins March 12. He played last season on a $4.9-million, one-year deal.

In the wake of Andrew Whitworth’s retirement after the 2021 season, the 6-foot 7-inch, 345-pound Jackson supplanted Joe Noteboom as the starting left tackle.

Last season Jackson did not play the first two games because he was suspended for violating the NFL’s personal-conduct policy. Upon his return to the lineup, he helped solidify a line that protected Stafford and cleared the way for running back Kyren Williams.

With the return of Jackson, the Rams could field the same offensive line that started the second half of the season, when the Rams bounced back from a 1-4 start to make the playoffs. That configuration included Jackson, left guard Steve Avila, center Beau Limmer, right guard Kevin Dotson and veteran right tackle Rob Havenstein.

The Rams have given interior lineman Jonah Jackson permission to seek a trade.