Bulger underwent an MRI exam on his groin and hamstring Monday and was due for a second MRI on what the Rams believed was a swollen knee. He also was to be tested for concussion-related symptoms Tuesday.
"Marc Bulger's pretty banged up," Spagnuolo said before the leg injury was revealed. "Marc's got a few things going on."
Spagnuolo was hopeful that guard Richie Incognito can return after missing three games plus the bye week with a foot injury.
The Associated Press contributed to this report.