Kittle sustained the injury during the first half of San Francisco's Week 1 win over Seattle. He exited the game at that point and was slated to undergo and MRI on Monday. Prior to getting hurt, Kittle had already caught four passes for 25 yards that included a 5-yard touchdown that gave the visitors a 7-0 lead.

George Kittle is going to be out three-to-five weeks, according to NFL Network's Ian Rapoport. He could be placed on Injured Reserve, which would force him to miss four weeks before being allowed to return.

The San Francisco 49ers just can't seem to stay healthy. After placing six players on injured reserve during the preseason — running backs Ameer Abdullah and Patrick Taylor Jr., wide receivers Jacob Cowing and Equanimeous St. Brown, and offensive linemen Andre Dillard and Isaiah Prince —some more of the 49ers' rosters are dropping like flies.