Littleton, 27, is a former undrafted free agent out of Washington signed by the Rams in 2016. He played out the final year of his three-year, $1,635 million contract before returning to the Rams on a one-year restricted deal worth $3,095,000 for the 2019 season.
The Raiders signed Littleton to a three-year, $36 million contract that included $22 million guaranteed last year.
In 2020, Littleton appeared in 14 games for the Raiders and recorded 81 tackles and no sacks or interceptions.
Kwiatkoski, 27, is a former fourth-round pick of the Bears back in 2016. He just finished the final year of his four-year, $2.915 million contract and made a base salary of $720,000 in 2019.
Kwiatkoski was testing unrestricted free agency last year for the first time in his career when he agreed to a three-year, $21 million deal with $13.5 million guaranteed with the Raiders.
In 2020, Nick Kwiatkoski appeared in 12 games for the Raiders and recorded 81 tackles, one sack, an interception, a forced fumble and four passes defended.