FONTANA, Calif. (AP) - David Reutimann saw Mark Martin's bumper in the mirror and took a deep breath.
It wasn't jitters exactly. Reutimann knew the NASCAR veteran - considered one of the cleanest racers in the business - wasn't going to cause any trouble as they battled side by side for most of last week's Sprint Cup event at Kansas.
Yet Reutimann also knows the stakes are different for the 31 drivers on the outside of the Chase for the championship than for the 12 drivers like Martin who are vying for a title.
Sure, Reutimann was racing to win. He just wasn't going to risk Martin's shot at finally grabbing the championship to do it.
"It's nerve-racking to race a guy in the Chase because you don't want to touch the guy," said Reutimann, who finished eighth, one spot behind Martin. "You don't want to be the guy that 'Well, if this hadn't have happened, such and such would have won the Chase or won the Championship.' You don't want to be that guy, none of us do."
It's a fine line the non-Chase drivers must walk during the 10-race Chase, which continues Sunday at Auto Club Speedway. It doesn't mean non-Chasers have to pull over like they're making room for an ambulance when a Chase guy gets on their bumper.
Yet the non-Chasers like Reutimann know there are only two ways to ensure yourself time in the spotlight during the Chase, win a race or ruin a Chase guy's day. And considering non-Chasers rarely make it to Victory Lane - Greg Biffle was the last to do it in 2007 - the alternative isn't that appetizing.
"But you can't roll over for those guys," said Reutimann, who was second in qualifying but will start 42nd on Sunday because of car failed post-qualifying inspection.
Maybe, but there is a certain amount of etiquette involved, a lesson Cup newcomer Brad Keselowski experienced in Kansas. Keselowski's No. 25 Hendrick Motorsports Chevrolet was working near the lead when he found himself in close quarters with Stewart and Juan Pablo Montoya, both Chase drivers.
Stewart, perhaps agitated by the way Keselowski was driving, radioed his concerns to crew chief Darian Grubb. A short time later NASCAR officials sent word to Keselowski's crew chief, Tony Eury Jr., that the 25-year-old driver needed to calm down. Stewart, however, didn't view it as situation where a Chase driver was getting preferential treatment.
"It was more a young rookie driver that was racing in the Nationwide Series or the Truck Series and that's how you race on Friday and Saturday, that's not how you race on Sunday," said Stewart, a two-time Cup champion. "I realize it's a longer race and there's more give and take. He's young. He's aggressive. He wants to do well. He wants to earn respect. He's got to understand you've got to be patient."
Keselowski, a surprise winner at Talladega in the spring, didn't take the call personally, though he remains a little confused about what exactly he did wrong.
"I thought it was somewhat humorous because it seemed the Chase drivers around me were the ones who were racing aggressively," Keselowski said. "I thought I was doing a normal deal."
NASCAR officials monitor drivers' conduct during the race and often relay any concerns to the offending teams. Vice president of competition Robin Pemberton said Keselowski wasn't singled out because he's not in the Chase.
"When we see things going on around the track that could affect the outcome of innocent bystanders and drivers that don't have a fight, we'll take and call a driver out on that," Pemberton said. "That's what we did."
Keselowski, who will drive Cup full-time for Penske Racing next year, isn't angry. He pointed out he wasn't penalized for his driving and has no plans to change his tactics going forward.
"I don't think NASCAR was threatening me," he said. "Much like a mom says you don't put your hand on a stove because it's hot. Is that a threat? No, that's your mom saying it's hot, don't burn your hand. If I had gotten into an accident with Tony, that stove would have been really ... hot." It's a stove that nobody wants to get near this time of year, particularly the Chase drivers. And much like Reutimann is particularly careful while driving next to a Chaser, the Chase drivers know when they're alongside a non-Chaser.
"Being in the Chase you've got to be aware that you're vulnerable," said Montoya, who comes to California third in the points behind Martin and Jimmie Johnson. "People kind of run over you pretty easy. I think you help yourself by giving them space because they don't have much to lose compared with us."
Besides, as Montoya has learned during his three years on the circuit the non-Chasers aren't the only ones to worry about.
"It's pretty interesting to see how guys in the Chase, they race you one way before the Chase started and now people are not really giving too much even early in the races," Montoya said. "It's kind of surprising ... (but) you just play the same game as they are playing."