McMillan has been diagnosed with a PCL sprain in his left knee, Jenna Laine of ESPN.com reports.
McMillan originally suffered a knee injury during training camp in early August, and this is believed to be an aggravation of that issue. The 24-year-old didn't play Week 1, logged just seven offensive snaps Week 2 and then lasted just two offensive snaps this past Sunday versus Minnesota before exiting due to the injury. Per Laine, the "early thinking" on McMillan's timeline suggests a 6-to-8 week absence, which makes him a candidate for IR. All of Ted Hurst, Tez Johnson and Kameron Johnson could be slated for larger roles with McMillan expected to be out for the foreseeable future.