Bears center Will Montgomery suffered a fractured left tibia in Sunday's win over the Raiders and has been placed on season-ending injured reserve, Brad Biggs of the Chicago Tribune reports.
Montgomery, who signed a one-year contract with the Bears this offseason due in large part with his familiarity with coach John Fox and offensive coordinator Adam Gase from his days in Denver, started the first four games at center for the Bears.
The team is expected to replace him in the lineup with rookie Hroniss Grasu, who has been inactive for all four games, or move left guard Matt Slauson over to center.