Royal signed a three-year deal with Chicago worth $10 million guaranteed in 2015, but played in just 18 games for the Bears because of injuries.
Royal's two-year stint in Chicago produced only 70 catches for 607 yards and three touchdowns.
A nine-year veteran, Royal had a career-high 91 receptions for 980 yards as a rookie with the Denver Broncos in 2008. Royal had another big year with the Chargers (62 catches, 778 yards, seven TDs) in 2014 that convinced the Bears to sign the 5-foot-10 slot receiver and reunite him with former Broncos head coach John Fox and quarterback Jay Cutler.
Royal, who will turn 31 on May 21, was scheduled to earn $5 million in 2017, but he had no guaranteed money left on his contract.