Before we overreact to one game — albeit one game that likely sliced the Vikings' playoff chances down to 25 percent if this data from FiveThirtyEight is any measure — let's start by saying that sometimes teams just lay an egg. For whatever reason or set of circumstances — in the case of the Vikings on Monday perhaps a mix of overconfidence and a weird West Coast start time — that can happen. One game is the ultimate small sample size. So what you're about to read is a reaction to one game, but not necessarily a projection for the next 15.

That said, the Vikings' 20-3 loss to the 49ers did for at least one game bring a whole bunch of question marks to the forefront. In short, everything that a reasonable person could be worried about going into the game proved to be legitimate concerns for at least one game:

*The makeshift offensive line, inconsistent at best a season ago before losing two key players for long stretches already this season, was subpar in many cases. Teddy Bridgewater was sacked five times (including the one captured brilliantly in that photo by the Star Tribune's Carlos Gonzalez), at least a couple of which were "no chance" plays with defenders in his face almost immediately. The Vikings gained just 248 yards of total offense, many of them meaningless. The failure to make more significant upgrades to both depth and quality on the line, a legitimate story line going into the year, remains at the forefront after week 1.

*Blair Walsh was the NFL's least-accurate kicker a season ago and was just 5 for 11 on field goal attempts during the preseason. On Monday, he continued to struggle by badly missing to the right an early 44-yarder that could have given the Vikings at least a little momentum in a scoreless game, then barely made a 37-yarder later. The Vikings financially committed to Walsh in the offseason, putting themselves in a bit of a bind. If he has one or two more shaky games, they might have no choice but to address the problem with some competition.

*The Vikings gave up 4.3 yards per carry and nearly 2,000 yards rushing last season, numbers that ranked in the bottom third of the NFL and made coach Mike Zimmer upset. There was optimism going into the year that the run defense would be better based on better linebacker play, but that certainly was not the case Monday. Carlos Hyde (who looked great, by the way) ran every which way over and through the Vikings for 168 yards and a pair of TDs. San Francisco as a team almost averaged 6 yards per carry. So consider the run defense a primary concern again. The defense did keep the 49ers to 10 points through three quarters, though, and can't be considered the primary culprit in last night's defeat.

*That designation falls to the offense, and here we get to the greatest hopes going into the year: that Bridgewater in Year 2, given a motivated Adrian Peterson, another receiver (Mike Wallace) and a healthy Kyle Rudolph, would take a leap forward that would mask the team's deficiencies and carry the Vikings into playoff contention. What we saw Monday, though, was this: a QB with happy feet (motivated at least in part by a leaky offensive line); receivers who struggled at times to get open, but a QB who struggled at times to find open receivers when given time; and a running back who very much looked like he had missed almost a full season. Bridgewater, Peterson and the offensive line were below average Monday. The Vikings have no chance if all three of those things continue, and the scary part is that all three are connected.

But again, it was just one game. The Twins looked like they were going to be historically bad this season after the first week, but things do have a funny way of working themselves out. If we get one-quarter of the way into the season and we're still talking about most or all of these things, though, concern could turn to panic.