Cromartie, 27, originally signed on with the Chargers as an undrafted free agent out of Wisconsin back in 2013. He lasted just over one season with the Chargers before signing on to the 49ers’ practice squad during the 2014 season.
San Francisco declined to tender him a restricted free agent offer last year and he later signed on with the Bills. After being released following last year’s draft, Cromartie joined the Seahawks but was placed on injured reserve coming out of the preseason and eventually released with an injury settlement.
The Lions signed Cromartie to a contract during the preseason before placing him on injured reserve soon after.
In 2016, Cromartie appeared in 10 games and recorded five tackles and no interceptions for the 49ers.
Demby, 22, was taken in the sixth round of this year’s draft by the Rams. He’s currently in the first year of his four-year, $2,616,620 contract.
The Rams waived Demby recently to make room for DT Aaron Donald on their active roster and he was claimed by the Lions.
During his college career at Maine, Demby was a four-year starter at left tackle and was selected as a first-team FCS All-American as a senior.