As the Minnesota Vikings reported for training camp, with no quarterbacks signed beyond the 2017 season and Teddy Bridgewater still rehabbing from his knee injury, there arose a school of thought that the team might be making a big mistake by not signing Sam Bradford to a long-term deal then and there.

Bradford said at the beginning of camp there had been no developments in talks with the Vikings about a long-term deal, as he prepared for a follow-up to the best season of his career with an improved supporting cast around him. With the price of a veteran starting quarterback only set to go up, the Vikings' decision only figured to get more expensive if Bradford had a strong 2017 season.

The state of the quarterback's left knee was something of a consideration then, given the fact he'd had two ACL operations on that knee, but it wasn't seen as a major deterrent to a long-term deal. It still might not be; the Vikings said again Tuesday the issues that have limited Bradford to six quarters in their first five games are non-surgical, and head athletic trainer Eric Sugarman said Bradford can "absolutely" recover from the wear and tear that's currently keeping him out of action.

But as Bradford approaches his 30th birthday next month and the Vikings await his return, it's getting harder to think the condition of his knee won't be a major consideration in the question of whether to give him a new deal.

Sugarman said Tuesday that Bradford's previous surgeries are "certainly a contributing factor" to his current issues, adding that "anyone that's had two ACLs is probably at risk" for arthritis in the future. It means that while Bradford can avoid a protracted post-surgical rehab, he also is theoretically at risk of a flare-up any time he gets his knee in an awkward position, as Sugarman said he did in Week 1. There's no quick (or permanent) fix, in other words, and knees generally don't get stronger as people age.

Bradford started 29 of his teams' next 32 games after his second ACL surgery — and one of the games he missed was the Vikings' 2016 season opener, which came just eight days after they acquired Bradford. But his issues now could be the kind of thing that crop up in the future, and the Vikings will have to ask themselves how much they want to commit to a player that might not be available for a handful of games at any given time.

Then there's the question of Teddy Bridgewater, who will be re-evaluated by Dr. Dan Cooper (the surgeon that performed his knee operation) next week and could return to practice shortly thereafter. The mere fact of Bridgewater returning to practice doesn't necessarily mean the Vikings will activate him from the physically-unable-to-perform list; they have three weeks to make that decision once Bridgewater starts practicing. But if the 24-year-old is healthy enough to return this season, Bradford's issues make it more feasible Bridgewater could get a chance to show why he should regain his job.

There are plenty of unanswered (and for now, possibly unanswerable) questions about Bridgewater's long-term health, too, and it's possible the right course of action for the Vikings is a quarterback with no history of knee issues, rather than one with two ACL operations and one with a knee dislocation in his past. The Vikings could certainly justify rolling the dice on one of the two passers, too; reliable NFL starters aren't exactly in great supply, and the Cowboys' history of crossing their fingers with Tony Romo's back issues shows how much risk teams are often willing to bear for the prospect of getting a QB who can perform at a high level.

But as Bradford's lingering injury issues show, the Vikings' choice isn't cut-and-dried, and might not be all that easy. It could, however, hold the fate of the team's current decision-makers, as well as a roster stocked with talented defensive players. Given all that remains difficult to discern, and all that's at stake, there might be good reason why the Vikings are taking their time.