Boone (quadriceps) is expected to be sidelined 4-6 weeks after undergoing an MRI on Friday, Mike Klis of 9News Denver reports.
Boone injured his quad during joint practice with the Vikings on Thursday. Surgery won't be required to address the injury, but Boone's recovery timetable does make him uncertain for the Sept. 12 regular-season opener against the Giants. The 26-year-old was putting together a strong camp and looks set for the No. 3 role behind Melvin Gordon and Javonte Williams when healthy.