Wagner (knee) suffered a sprained kneecap in Sunday's 51-29 victory over the Lions, Michael-Shawn Dugar of The Athletic reports.
Wagner underwent an MRI following Sunday's contest, which fortunately revealed he did not suffer any major damage. He was able to walk off the field under his own power but was ultimately kept from returning. His status for Week 18 is undetermined. Given the Seahawks have been eliminated from the playoff picture, it would not be surprising if they err on the side of caution with their starting middle linebacker.