Jonathan Cooper sustained a fracture to his left fibula during the team's 24-7 pre-season defeat to the San Diego Chargers last night, the team has confirmed.
A report on the NFC West side's website says that the guard, who was the seventh overall pick in this year's draft, is likely to be out for the season, although head coach Bruce Arians is hopeful that he may be able to return late on.
The 23-year-old had played in both of the team's pre-season wins earlier this month.
The team will also send five players for MRI scans on knee and ankle injuries, while wide receiver Andre Roberts will have a scan on a quadriceps injury.
