Helio Castroneves was not so much absent, just absent from a race car and dressed more casually at the season-opening Firestone Grand Prix of St. Petersburg on March 11.

For the first time in two decades, the popular Brazilian has a primary responsibility of driving something other than Indy cars. He's now a full-time member of Team Penske's sports-car effort.

The effervescent three-time winner of the Indianapolis 500 had plenty of duties as the St. Pete grand marshal, an honor earned by winning a record three times on the temporary street course. Still, Castroneves had ample opportunity to amble into official Team Penske functions with former INDYCAR teammates Josef Newgarden, Simon Pagenaud and Will Power. It was a poignant reminder for Castroneves of how much he missed the Verizon IndyCar Series already.

Their paths will not cross as much with the Verizon IndyCar Series season underway and Castroneves’ IMSA WeatherTech SportsCar Championship slate full. Along with co-drivers Ricky Taylor and Graham Rahal, he contended for the lead in Saturday’s Mobil 1 Twelve Hours of Sebring until their Acura DPi retired from the endurance race due to a lack of oil pressure.

Castroneves rejoins the Team Penske INDYCAR program today for the series’ open test at Barber Motorsports Park in Birmingham, Alabama. It’s his first preparation to team again with Newgarden, Pagenaud and Power for the INDYCAR Grand Prix and 102nd Indianapolis 500 presented by PennGrade Motor Oil in May at Indianapolis Motor Speedway.

Until then, the next two months will begin to define how much Newgarden, Pagenaud and Power as individuals and a team miss the driver that preceded them in providing owner Roger Penske coveted Indianapolis 500 wins and stamping the post-Rick Mears template for driver-turned-lifetime employee.

“Helio is going to be a big loss. We all love working with him,” Pagenaud said. “He’s such a joy. And he brought a lot of good mood in the team and also of an image, paternity, I would say almost. That was interesting, to have him around. And for me, it was a great example of what to be like, to be the perfect Team Penske player.”

The overt personality that made Castroneves, 42, one of the most recognizable and magnetic personas in the series, enabled his participation on “Dancing with the Stars” in 2007, when he won with pro partner Julianne Hough, also made him a valuable Team Penske component.

“We are always going to feel his energy loss,” Newgarden said. “Helio always had good energy, pretty much everywhere, all the time. He’s just very enthusiastic and he’s always positive and I think that was always good for all of us, whatever we were doing. We’re going to miss that.”

But Castroneves was more than a personality. Though he never won an Indy car championship, he has amassed 30 victories – including the legend-making Indianapolis 500 three times, one shy of the record shared by A.J. Foyt, Al Unser and Mears – and was a valuable asset to Power on the ovals that comprise six of 17 races this season. The series next visits ISM Raceway for the Desert Diamond West Valley Casino Phoenix Grand Prix on Saturday, April 7 (9 p.m. ET, NBCSN and Advance Auto Parts INDYCAR Radio Network).

“(Castroneves) and I were really comparable on setups, especially on the ovals,” Power said. “Our feedback matched and our setups matched. That’s where I found Helio to be the best to lean on, for me. I could actually go to his setup and be pretty good.”

That’s not to say Newgarden, Pagenaud and Power expect to come unhinged in Castroneves’ absence this season. Eliminating one car reduces the amount of information the team can apply to the collective effort, but may mitigate overload.

“I thought four (drivers), at times, was a little overwhelming,” said Pagenaud, the 2016 Verizon IndyCar Series champion. “It’s a lot of information and difficult, sometimes, to look at everybody’s (data) between sessions and sometimes it drove – not just me – but it was difficult to make the right decision or think that you made the right decision, just because you have so much. So, I think just downsizing a little bit will help getting to the point quicker.”

Newgarden deemed the new workflow more “concise” at St. Pete, but noted the value Castroneves might bring at Indianapolis. In an oddity for an organization that has won the Indianapolis 500 a record 16 times, for the first time since 2001 Team Penske begins a season without a former winner of the race in its full-time lineup.

Simulator work has led Castroneves, the 2017 Indianapolis 500 runner-up to Takuma Sato, to believe the new universal aero kit on all cars will harken to a previous generation of car he enjoyed.

“I’m assuming I’ll jump in and it’ll take two laps to get used to, and then back in the game again,” said Castroneves, scheduled to turn laps in the No. 3 Team Penske Chevrolet on the Indianapolis Motor Speedway on March 27 as part of another series open test. “The simulator, it was rolling back time when to we used to drive the 2004-5-6 car. You don’t brake as deep and the car, obviously on acceleration, does something. You have to think of a new approach instead of being so aggressive. You’ve got to read the car, what the car is doing. In fact, last year (when the previous aero kits had much more downforce), you jump in the car and you brake as hard as you can, you push as hard as you can and you keep pushing pushing, pushing.

“You can’t just go sit down and go flat out right away like people used to. I think the experience will help me go back in time a little bit, go back to the compartment I didn’t use for long time.”

Power is interested in seeing Castroneves in an Indy car again, given the Australian considered 2017 the “best year I’ve ever seen him perform.” Castroneves finished second twice, third, fourth and fifth in the final standings in his last five Verizon IndyCar Series seasons, winning three races.

“He’s just been strong,” Power said. “He could have plugged into a car this year, I guarantee, and he would have been a championship contender again.”

Now, Newgarden, Pagenaud and Power are in the process of learning how unplugging Castroneves affects their championship aspirations.