Nick Williams has accepted a pay cut to keep his roster spot with the Lions. The defensive tackle will now earn $1.25MM in base salary this year, down from $4.1MM last year (Twitter link via Dave Birkett of the Detroit Free Press). In exchange, Williams will also get $500K in guaranteed money, though his per-game roster bonus will go down from $400K to $250K. 
Williams, a 2013 seventh-round pick, has managed a lengthy pro career. In 2019, he turned in a career year with new watermarks in tackles (42), and sacks (six) for the Bears. He parlayed that into a solid payday with the Lions, but he was less impressive as a full-time starter. Last year, he had 23 tackles and one sack in 14 games (13 starts).
The extra coin could allow the Lions to pursue other free agents still on the board, including slot specialist K’Waun Williams.
Now it makes more sense why they cut Danny Shelton and kept Nick Williams. Nick was willing to take a pay cut. Pretty significant one too.
This was a overpay from the get go anyways.