So we're two games into the Vikings season and they've already used two starting quarterbacks — Sam Bradford in Week 1, who was brilliant but dinged his knee along the way, and Case Keenum in Week 2, who was not brilliant and dinged fans' optimism along the way.

One of those two guys will probably start next week against Tampa Bay, but these being the Vikings one never really knows. Head coach Mike Zimmer didn't exactly restore a sense of calm to the purple faithful when he said after Sunday's 26-9 loss to Pittsburgh in regards to Bradford's injury, "I'm not going to discuss it with you. He's going to be OK, OK? Sam will be the quarterback; it's going to be OK. Maybe the next week, maybe six weeks from now, he's going to be OK. It's a nonsurgical issue. He'll be fine."

Sorry if the part of that sentence I gravitate toward is the part about "maybe six weeks" and not all the assurances Bradford is going to be fine. It might have just been a frustrated Zimmer talking, but if that's a possible realistic timetable, we're talking about midseason.

Still, it seems more likely than not at this point that Bradford's injury is a short-term thing. And it stands to reason that even if Bradford can't play next week the Vikings would turn again to Keenum.

But … it also stands to reason that if Bradford is having non-surgical issues with the same left knee that was surgically repaired in 2013 and 2014 after ACL tears, this could be a recurring problem throughout the season. If we put Bradford's health in a gray area and project more struggles onto Keenum, that's where things get really interesting for the Vikings' short-term and long-term QB questions.

Let's say Bradford can't play next week and Keenum is either terrible or injured. The Vikings would then need to turn to Kyle Sloter — activated from the practice squad Saturday to be Keenum's backup. Let's say Sloter, who was impressive enough in the preseason for Denver that the Vikings gave him a hefty practice squad salary, was impressive when given an opportunity. He could find himself starting Week 4 against the Lions depending on the status of Bradford and Keenum.

Now fast-forward a few weeks. Let's say the Vikings have made it through the first eight games before the bye week in decent shape despite having to cobble together a plan at quarterback. And now let's factor in this Sunday report from the NFL's Ian Rapoport, who said Teddy Bridgewater is expected to be ready to play by midseason.

If Bridgewater is truly healthy, he immediately becomes at least the Vikings' best backup option. If Bradford's knee continued to act up, would it be crazy to think Bridgewater could start some games for the Vikings this season? Not at all.

So it's entirely possible to see a scenario where the Vikings use four different starting quarterbacks this season (or perhaps even more since the four QBs in question are two guys with a history of major leg injuries, an unspectacular backup and a practice squad guy).

Or Bradford could start the next 14 games and this will have been an exercise in futility.

This being the Vikings, I'll let you decide which is more plausible.

And I'll leave it up to Rick Spielman to sort out what the QB plan is for 2018 and beyond.