When the Vikings drafted Adrian Peterson in 2007 an old cliche still stood — to win in the NFL teams must be able to run the football.

Since then, Peterson has become the face of the franchise, one of the most recognizable players in the league and crucial to the Vikings’ stadium drive. While he’s become an off-the-field phenom, his value is plummeting on the field.

Peterson signed a seven-year, $100 million contract on Sept. 18, the same week NFL quarterbacks passed for a combined 7,842 yards. Vikings quarterback Donovan McNabb threw for a league-low 39 yards, and the team ran the fewest offensive plays in the league in a 24-17 loss to the San Diego Chargers. The Tennessee Titans, one of the NFL’s only other run-first teams, ran the second fewest plays in a loss to the Jacksonville Jaguars.

See a trend?

Despite what should have been a 100-yard rushing game by Peterson (a botched snap left him with 98), the Vikings lost its season opener and its play calling was criticized during the following week.

Meanwhile teams whose quarterbacks who threw for more than 300 yards in Week 1 thrived even if their featured backs didn’t.

• Aaron Rodgers passed for 312 yards and, James Starks rushed for 57 yards in the Packers’ 42-34 win over the Saints.
• Jay Cutler passed for 312 yards, and Matt Forte rushed for 68 yards in the Bears’ 30-12 win over the Falcons.
• Matthew Stafford passed for 305 yards, and Jahvid Best rushed for 72 yards in the Lions’ 27-20 win over the Buccaneers.
• Tom Brady passed for 517 yards, and Danny Woodhead rushed for 69 yards in the Patriots’ 38-24 win over the Dolphins.

Peterson was even more electric in Week 2. The star running back had 25 carries for 120 yards and two touchdowns, but a comeback led by Tampa Bay quarterback Josh Freeman’s passing attack left the Vikings with a second consecutive loss to start the season.

Peterson is the highest paid running back in NFL history and the investment requires he be a major part of the Vikings’ offense. The consensus is he’s the league’s best running back but that title means less and less and the passing game becomes more important.

Teams whose quarterbacks lead the young season in passer rating are a combined 8-2. The league’s leading rushers’ teams are 6-4 — not bad, but their wins weren’t nearly as convincing as those of the Patriots, Packers, Lions or Saints.

Peterson may be the most talented player in the NFL, but running backs don’t win games anymore, and as a result fewer teams will be making the same investment in them that the Vikings did.

Of course, Peterson’s value goes way beyond the field. Zygi Wilf is serious about keeping the Vikings in Minnesota and signing Peterson was a major start.