Coach Jim Caldwell did not give a timetable for Bethea's return. Caldwell said Bethea would be fitted for a cast and would return when he can play while wearing the cast.
Losing Bethea is a blow to a Colts defense that is still missing safety Bob Sanders. Caldwell said Wednesday morning he wasn't sure Sanders would be back for the regular-season opener. Sanders had offseason knee surgery to clean up the same knee that kept him out of 10 games last season.
Bethea went to the Pro Bowl in 2007, the same year Sanders was the NFL's defensive player of the year.