Sam Bradford couldn't play Sunday because of a sore knee. Xavier Rhodes came out at times because of a hip injury, and perhaps other undisclosed ailments.
Once Bradford was ruled out, Sunday's game became more about survival than competition. Six days after Bradford put together his best game as a pro, he left the team's current and future situation at the quarterback position in doubt, which left the Vikings' ambitions in doubt.
Case Keenum is not the answer to any question that involves making the playoffs, and the Vikings can't know that Bradford will be ready for next Sunday, given how gingerly he moved while trying to warm up on Sunday night.
The promise of the Vikings' opening-night victory melted on a hot day in Pittsburgh, in a 26-9 loss that felt like an exercise in hopelessness. If Bradford returns to full health, the Vikings may be favored to win their next three games. If not, they'll have trouble beating anyone.