Mike Wallace missed practice on Monday and is "day-to-day" with a sore knee, according to ESPN's Ben Goessling. He also missed Minnesota's only practice before the bye-week break.
Adding to the uncertainty at the wide receiver position, fellow starter Charles Johnson still hasn't fully recovered from a rib injury that kept him out the last time Minnesota played.
The Vikings need Wallace on the field, as he's the team's leading receiver with 20 catches for 233 yards and a touchdown this season. The Vikings were lucky enough to discover reserve receivers Stefon Diggs and Adam Thielen, who combined for 12 catches and 157 yards against the Broncos in Week 4. They could have a big role again if Wallace and Johnson would be out Week 6.