Terms were not disclosed. To make room on the roster, the Lions released linebacker Andre Collins.
Howard, a former Heisman Trophy winner at Michigan who won MVP honors in Super Bowl XXXI, averaged 19.2 yards on 19 kickoff returns and 7.8 yards on 12 punt returns this season for Green Bay before being sidelined with injuries to his fingers on both hands.
Before the 1997 season, Howard signed with Oakland. Last season with the Raiders, he ranked fifth in the AFC in punt returns but again failed to establish himself as a receiver. In June, he signed a four-year, $5.71-million contract to return to the Packers.