ST. PETERSBURG, Fla. -- Sarah Fisher was striding from the paddock, past the pedestrian bridge over the Grand Prix of St. Petersburg street course last spring, making sufficient time to reach pit road before IndyCar practice began.

A middle-aged man approached. His fumbling verbal entree suggested he thought Fisher -- a trailblazer as a driver and owner -- was Simona de Silvestro, the popular Swiss racer who had finished a rousing fourth at St. Petersburg in 2011. Fisher politely conveyed her name, whereupon the man asked if she was racing that weekend. Patiently, she informed him she was a team owner now, and the awkwardness seemed to overcome the man sufficiently to let her walk on her way.

There is less chance of such confusion when the IndyCar season commences this weekend again on the streets of St. Petersburg. If the man or his 2014 incarnation is paying any attention at all, he already will be aware that the series that had featured at least one full-time female driver every season for the past decade, and a record-tying four in the Indianapolis 500 last year, will have none on the grid this Sunday. And the prospects are not good for the near future.

There is no conspiracy. There is no real explanation, several female drivers say. It's partly the ever-present state of sponsorship acquisition in a form of motorsports struggling for market share in the shadow of NASCAR. It's partly cyclical. And in an odd way, said former Champ Car and IndyCar driver Katherine Legge, it may be symbolic of a gender-free dynamic in open-wheel racing.

"I'm not frustrated by it, but it's surprising to me," Fisher said. "I wish there was someone here, for sure. There's certainly a void in our sport."

The 2014 season will mark the first IndyCar campaign since 2004 and just the fourth since 1997 without a full-time female driver. The last void occurred when Fisher explored a possible NASCAR career from 2004 to 2006. Danica Patrick, open-wheel racing's most successful and popular female driver before transitioning to NASCAR, did not make her debut until 2005. Legge raced in the developmental Toyota Atlantics circuit in 2005 -- winning three races -- then ran two Champ Car seasons before the series went bankrupt and was amalgamated into IndyCar.

Last season, de Silvestro, Legge, Ana Beatriz and Pippa Mann tied the 2010 mark -- set by Patrick, de Silvestro, Fisher and Beatriz -- of four women in the 33-driver Indianapolis 500 field. Females were so commonplace in IndyCar that tying the record went relatively unheralded, which could be seen as a subtle milestone of gender equity in the series. But that also makes the current void feel a little odd, Fisher said.

After her best season in IndyCar, Simona de Silvestro left to work as an affiliated driver for Sauber F1 Team. AP Photo/Keystone/Ennio Leanza

And it might last a while, unless de Silvestro, who left to work as an affiliated driver for Sauber F1 Team this season, opts to return next year. Legge, Mann and Beatriz have been unable to secure full-time IndyCar rides. There are three females in the "Road to Indy" developmental ladder -- Julia Ballario, Vicky Piria and Michele Bumgarner in the Pro Mazda series, the middle of three rungs, generally two-three years away from a shot at IndyCar. Highly regarded prospect Ayla Agren is going to contest another season in the F1600 Championship, which is not part of the official series system.

Jason Penix, who is IndyCar Director of Development Series, said the series prides itself on diversity.

"I don't know that there's a great explanation for why we don't have as many female competitors as in the past," he said. "If anything, I would place the blame on timing.

"Naturally, it takes a few years for the young drivers to make their way to the top, but certainly when you have a bit of a gap like we do today and don't have a female driver competing full-time at the top of our sport, the absence is noticeable."

Fisher said although the volume of female drivers in IndyCar could be cyclical, the current dearth could "be a little bit of a wake-up call to [the series] now."

"I don't think they've ever had to worry about it," she said of a series that has brandished its gender equity in the past. "With some of the young ladies that have aspired to drive in the Indy 500 and IndyCar, they were lucky in that they just sort of inherited some hard-working drivers who put it together and got here. They haven't ever had to strive for that diversity support, I guess.

"They haven't been sort of feeding that channel with an initiative."

Fisher, who joined the Bill McAnally Racing/Richard Childress Racing Development Program in 2004 when a diversity wave swept NASCAR, said she is unsure if IndyCar should be in the business of cultivating certain sectors of society.

Former IndyCar driver Katherine Legge now drives for Delta Wing in the United SportsCar championship. AP Photo/Darron Cummings

"I'm the type of person where it's all about the bottom line," Fisher said, "so to target genders and minorities and that sort of thing, I feel like you don't exclude folks from that, but you try to get the very best drivers regardless of who they are."

But even those are often hampered by sponsorship woes. De Silvestro constructed her best IndyCar season in 2013, finishing 13th in points and producing a career-best second-place result at Houston, but had no IndyCar offers that didn't necessitate her acquiring most of her funding for this season.

"In general, I don't think [a lack of females in IndyCar] is because women can't get into IndyCar anymore," she said. "You have to be competitive, but you also have to have people behind you to support you."

Legge, who now drives for DeltaWing in the United SportsCar championship -- and became the first female to lead an American Le Mans Series race last year -- said a greater female driver population has reduced women's uniqueness with sponsors. She last contested an IndyCar season in 2012 as part of a TrueCar-sponsored "Women Empowered" campaign but was jettisoned for Sebastian Saavedra last year.

"Back when Danica was doing IndyCar and I was doing ChampCar, there was definitely an element of uniqueness and, I don't know, like novelty, I guess," Legge said. "And so yes, it got the attention and we got coverage and therefore we got the attention from sponsors. And now, it seems like there are many, many more women involved and even though it's still nowhere near the level of the guys, it's all of us and it doesn't seem to help in the funding stakes.

"I think in a way that's a good thing and in a way that's a bad thing. I would love to have sponsors knocking at my door, but it just goes to show we're not a novelty anymore and that we're just race car drivers."

And in the IndyCar series, their absence is felt.