Through 12 starts this season, the St. Brown leads the Lions with 75 receptions, 884 yards and nine touchdowns.
Detroit (7-5) sits in the No. 8 seed in the NFC playoffs after losing twice in its previous three games, just one spot ahead of the Cowboys (6-5-1) in No. 9.
However, Dallas is riding a three-game winning streak heading into Thursday’s highly-anticipated game.
Going into extra time without St. Brown would have been a huge blow for the Lions, even more so given that the Jared Goff-led offense is already operating without tight end Sam LaPorta, who is out for the season with a back injury.
Even if St. Brown plays, a bigger contribution could be in store for Jameson Williams, who has recorded 38 catches for 706 yards and six touchdowns this season.
The Cowboys and the host Lions kick off Thursday at 8:15 PM ET.