What if Robert Griffin III is the next JaMarcus Russell instead of the Redskins’ savior? Unlikely as that is, it would prove that the NFL’s new low rookie pay scale -- designed to protect teams from big contracts for unproven players -- works. But anyone with a TV can see how adidas and Subway are wagering their 2012 sales on RG3 before he has thrown an NFL pass. What protects them from making a bad investment on a guy who could flunk this fall?

Nice of you to worry, but marketers understand the risk of ending up with a Russell, the No. 1 pick in ’07 who was out of the league after ’09 with only the $30 million the Raiders paid him to show for it. Marketers evaluate talent differently than teams do. With Griffin, they’re following what we’ll call the four rules of rookie marketing.

JUST BUDGET IT: Brands plan to spread deals around to all the high picks and hope one or two pay off. “They put money aside every year,” said Doug Shabelman, president of Burns Entertainment & Sports Marketing. “But it’s not a huge part of an overall company budget.” And once he’s signed, the chances an NFL player ever switches to another brand are pegged at only 10 to 25 percent. Should RG3 have the Midas touch marketers hope for, there’s no limit to what they can pay him -- or how much he’ll earn for them -- down the road.

A GOOD DEFENSE IS BETTER THAN A GOOD OFFENSE: It’s odd to say, but Griffin’s deals -- an estimated $3 million from adidas and mid-six figures from Subway, plus more from EA Sports, apparel maker EvoShield, Gatorade and Castrol -- might be owed partly to caution rather than to a conviction that he’ll be a superstar. Companies often lock up players just to keep them from competitors. “You can’t take that chance,” said advertising executive Bob Dorfman, who produces the Sports Marketers’ Scouting Report.

BEHIND EVERY RUSSELL THERE’S A BUSH: Russell was a disaster: 23 interceptions and just 18 touchdowns before being cut. But Reggie Bush proves top picks don’t need All-Pro stats to be pitchmen. Bush was the No. 2 pick in ’06 and signed with adidas. He hasn’t been to a Pro Bowl, yet he moves enough product to be worth $5 million a year in endorsements. RG3 could do far worse.

SOME GUYS REALLY ARE SPECIAL: “If you look at the most iconic recent marketing stars -- Jeter, Manning, Jordan -- Griffin is ahead of them at the same age,” said John Stone of the New England Consulting Group. “As far as charisma, ability to communicate, authenticity and being a refreshing personality, he has the potential to be as big a superstar as those athletes.”

Those are big shoes to fill, but then again, brands don’t want RG3 to fill shoes. Just to sell them.