Newly acquired quarterback Sam Bradford made a difference to the Minnesota Vikings offense, and the team is now 2-0, with a win over their main divisional rival the Green Bay Packers. But they won’t be Super Bowl contenders as long as the offensive line remains as bad as it has been.

Star running back Adrian Peterson went off injured against Green Bay with a knee injury that is expected to sideline him for some time but not shut him down for the season, but the way the offensive line is playing it might not make a huge difference.

Peterson gained 19 yards on 12 carries against the Packers, but he gained 20 after contact. He was being hit behind the line on average. Matt Asiata, Peterson’s replacement, gained 13 yards on six carries, 10 of which came after contact. Jerick McKinnon gained two yards on two carries. As a team, the Vikings rushed for 29 yards last night, and 30 after contact.

Peterson had two of his biggest gains (five and four yards) heading off right or left end – in other words, he was trying to get around the line entirely.

We have seen in the past that Peterson is capable of getting things done despite poor blocking up front, but at his age it likely can’t be relied upon, and now with his knee injury he himself can’t even be relied upon for the team.

It is possible to succeed with below-average or even bad offensive line play in today’s NFL, it’s just a lot harder. The Seattle Seahawks have been consistently doing it for years, but they have Russell Wilson, had Marshawn Lynch and the threat of the read/option to stress a defense and effectively “block” a free defender (because he had to hold in place waiting to see whether the quarterback kept the ball or not) when they wanted it done. The Vikings now have none of those elements, and what’s more concerning is that the line was even worse in pass protection than it was run blocking against the Packers.

As a unit they combined for 17 total pressures. Each lineman only had 36 pass-blocking plays to contend with, and yet every member surrendered pressure, and Joe Berger was the only one to escape without allowing multiple pressures. Through two weeks of action the Vikings now have three of their linemen rank in the bottom five of their position in PFF grade. Matt Kalil (36.9), Andre Smith (40.0) and Brandon Fusco (38.1) are all struggling badly, and expensive free-agent acquisition Alex Boone (54.2) isn’t much better than that level. Center Joe Berger has been the team’s best lineman, and his 73.6 grade is both hardly stellar and a massive drop from the 88.0 grade he had a year ago.

The line alone right now is a prohibitive cap on Minnesota’s prospects this season. You can win a Super Bowl with a line this bad, but it takes a QB playing at an unsustainably elite level in the face of pressure — like Giants QB Eli Manning was able to during the 2011 season. During that regular season, the Giants offensive line allowed a league-leading 222 total pressures. Right now, the Vikings are on pace to surrender 224.

The most optimistic Vikings fan on Earth would find it tough to imagine Sam Bradford going on the kind of run that Manning did in 2011. Manning himself has never come close to replicating it, and the Giants have never come close to contending again as a result.

Bradford is a quarterback capable of winning the Vikings games, as last night’s 87.2 game grade showed. With the impressive defense they have in place, and with a strong start to the season, they would be well placed to make a run, but their offensive line is simply too bad right now to think seriously about a Lombardi Trophy at the end of the season. It will need to take a significant step forward for that to happen.

Losing Peterson for an extended period of time is a big blow to this offense, but as things stand, Peterson was taking the hand off and then running into a brick wall of purple bodies at the line – if he was lucky. His average carry this season has seen him gain just 0.19 yards, or about seven inches, before being hit by defenders, and you’re just not going to get it done on the ground with that kind of blocking.

At 2-0, sitting atop the division and with the first showing from Bradford a very good one, there are several reasons to be happy for the Vikings. But if this team wants to be anything more than that, they need to be thinking seriously about what they can do to improve the performance from the O-line, because right now it’s what is going to curtail the success of the season.