Lions coach Jim Schwartz said at the start of the week that wide receiver Calvin Johnson’s knee injury was not anything serious. Maybe. But it looks like it could be serious enough to keep him out of Sunday’s game at Green Bay, not a good sign for a Detroit offense that could also be without quarterback Matthew Stafford.

Both players were missing from practice this morning, according to Tom Kowalski of MLive.com. Johnson suffered a knee injury in the loss to Pittsburgh last Sunday, and Stafford's knee was injured two weeks ago when he was sacked by the Bears’ Adewale Ogunleye at Soldier Field.

Daunte Culpepper will start in place of Stafford if he cannot go. The Lions will have to try to replace Johnson by committee if he cannot go.

Detroit has not won at Lambeau Field since 1991.

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