Buccaneers head coach Todd Bowles said that Winfield was diagnosed Monday with a "slight rib fracture" and will miss 2-to-4 weeks, Jenna Laine of ESPN.com reports.
Bowles officially ruled Winfield out for Thursday's game against the Cowboys, and the seventh-year safety would seemingly face an uphill battle to make it back for a Week 6 matchup with the Steelers on Oct. 18 after suffering the rib injury in Sunday's 17-14 loss to the Packers. Through Tampa Bay's first four games, Winfield had 24 tackles and one forced fumble. Ifeatu Melifonwu is slated to replace Winfield in the starting lineup Week 5.