He didn't practice Monday and will miss practice again on Tuesday, coach Mike McCarthy said, adding that Lacy was "very sore."
"I can't see him playing'' against the Bears, the source told ESPN.
Related players: Knile Davie, Don Jackson
Lacy's availability for Thursday night might have played a role in motivating general manager Ted Thompson to make his first player trade since 2010, getting Knile Davis from the Chiefs. The Packers also will promote rookie running back Don Jackson from the practice squad for Thursday night, a source told ESPN's Rob Demovsky. The plan is for Jackson to be active Thursday night against the Bears so the Packers are not left with just one natural halfback, as they were against the Cowboys.