Kirk (knee) will miss Sunday's game against Las Vegas and may need surgery for a meniscus injury, David Lombardi of SFStandard.com reports.
After opening the year on injured reserve with a calf injury, Kirk finally got healthy and played 20 snaps in a Week 7 loss to Atlanta. Other injuries at wide receiver opened up an opportunity, but now it seems Kirk is more likely to go back on IR than make an impact in the coming weeks.