The Detroit Lions had a slim chance to make the playoffs heading into their Christmas Day game against the Minnesota Vikings, and a dismal 23-10 loss eliminated them officially. So all that's left to play for in Week 18 against the Chicago Bears is an above .500 record for the season, or possibly impacting the Bears' playoff seed by beating them.
The Vikings and Lions have matching 8-8 records heading into the final week of the regular season, with Minnesota of course holding the tiebreaker for third place in the NFC North via their season-sweep.
So with a loss to the Bears in Week 18, the Lions can assure themselves of a fourth-place finish in the division.