The Lions had been looking for linebacker help at the combine, and Worrilow should compete for a starting spot on Detroit's defense, while also contributing on special teams. He is the type of versatile player Lions general manager Bob Quinn typically looks for.
Worrilow, who will be 27 once the 2017 season begins, was the Atlanta Falcons' leading tackler for three consecutive seasons before losing his starting job to rookie Deion Jones in 2016, as the team wanted more speed at the position for coverage purposes.
His primary role in 2016 was on special teams, although he started a game due to injury.
Worrilow joined the Falcons in 2013 as an undrafted player out of Delaware. He started 12 games a rookie. His career numbers include 386 tackles, three forced fumbles and two interceptions in 2,762 defensive snaps.
ESPN's Michael Rothstein and Vaughn McClure contributed to this report.