Stafford failed to practice each day this week and was listed as out with a back injury, according to the team's official injury report. Lions head coach Matt Patricia told reporters Friday there "is a medical plan in place" for the quarterback, but didn't reveal additional information.
Stafford, who made 136 straight starts before missing last week's game against the Chicago Bears, will now miss his second consecutive contest. Backup quarterback Jeff Driskel filled in for Stafford and completed 27-of-46 passes for 269 yards, one touchdown and an interception.
In eight games this season, Stafford has completed 64.3 percent of his throws for 2,499 yards, 19 touchdowns and five picks. Earlier this year, he became the fastest quarterback in NFL history to reach 40,000 career passing yards.
The Lions (3-5-1) will host the Cowboys (5-4) on Sunday before traveling for a matchup against the Washington Redskins on Nov. 24.