Beyond his appreciation for Penske’s continued trust and faith, Allmendinger has been warmly received by Will Power, who clearly has a fondness for pressure. With Penske's interest in seeking a new teammate that could turn up the heat on Power, Allmendinger was a brilliant choice, and after a recent outing in Power’s kart—one where Allmendinger went a tenth faster than its owner—a friendly rivalry is already brewing.

“If I could jump in an Indy car and go a tenth quicker than Will right away, I’m pretty bad ass,” said Allmendinger, “but it's going to be a lot more work than just jumping in his go kart. You could argue that when it comes to outright speed he's been the fastest man in IndyCar for the last three years. Obviously, for whatever reason, things have happened and he hasn't won the championship, but it is what it is. But I watched it for the last three years and he, to me, is one of the fastest, if not the fastest.”

Allmendinger is, understandably, feeling his own sense of pressure to measure up against Power in equal Penske machinery, but doesn’t expect his 2006 form to return all at once during a single-day test.

“Here's the deal. I've got to go to Sebring and act like, in a way, I have nothing to lose and everything to gain, but at the same point, it's me and I know myself and I'm going to go there and put pressure on my shoulders to go out there and get up-to-speed quick and go hard there," he said. "Not necessarily be the fastest guy out there but at least be in the game and feel good about one day being in the car for the last seven years and go out there and feel comfortable that I’m at least right there.

Michael Cannon, left, and Allmendinger, right, formed a powerful combination in 2006. Will he be able to do the same with Ron Ruzewski at Team Penske? (Photo: Marshall Pruett)

“Will and Helio, those guys, they're obviously some of the best in the series so I've got great guys to learn off of and great data to learn from and great guys to talk to. But by no means am I sitting here talking to you going, oh yeah, I'm laying it down to Will Power at Sebring. That's not what it's all about. It’s about me just getting comfortable and hopefully going and doing a good job and maybe making something of it from there."

Compared to some of the fluffy physiques found in NASCAR, Allmendinger has always maintained a high degree of fitness and strength training which should make the transition from Sprint Cup back to open-wheel less of a challenge.

“Believe me, it'll still be an adjustment, those cars are physical and when I used to race Champ Car it was tough and that’s what made it fun was the fact that I felt like you went out there and if you trained hard and you did what you needed to do that you were in an advantage in the car and you were strong," he said. "At the end of the race when you were tired, you were maybe stronger than the next guy you were battling.

“I guarantee I’ll be tired after the test day but, honestly, I can't feel anything different than I usually do. Put it this way, I'm the lightest I’ve been in six years anyway, weight-wise. I’m at the gym every day for two hours, doing cardio, weight lifting, core work. It’s no different than what I've done in the past how many years at NASCAR. The only difference, honestly, is the fact that now I can be actually in a routine again. Getting ready for a NASCAR season you have a little bit of winter and then you’re gone again for three or four days at a time or a week and it’s hard to get into a routine. And that’s the only difference from being back in open-wheel racing, at least I can get into a routine every day and I've done that over the last, really, over the last few months trying to get back into the routine and working on that.”

If there was a knock on Allmendinger in Champ Car, and again in his first few seasons of Sprint Cup, it was his lack of technical expertise. Prior to joining Forsythe, Allmendinger struggled mightily at times at the new RuSport team, and it was largely attributable to the bad combination of an inexperienced team and raw driver being unable to find the right chassis setups.

With Forsythe, the championship-winning team had all of the setup data required to give Allmendinger rocket-fast cars, which he then exploited to such great success.

Now, years later, and with questions still remaining about his chassis feedback and grasp of racecar engineering, Allmendinger believes he will be in a far better position to help Penske’s Ron Ruzewski tune the car to his liking.

“I think the biggest thing is that what I grew up doing the whole time and it just came natural," he said. "It's going to take a little bit of work to get in back in the flow of it and feel what this car’s supposed to do and what I feel but, obviously, when you get older you kind of get more experience and figure out what is natural and what you need to work on. You can’t just go off natural talent like I used to.

“For me, it's just really about studying. It's about studying the data, studying the driver graphs; what makes Will Power so fast, what makes Helio so fast? And overlaying that and studying it. I know I'm going to be behind the car, for sure. It's going to be me trying to catch up to the car all day and getting used to it. We'll see, by the end of the day, if I'm really comfortable, make some big changes, see how they feel; if not, just keep running laps. But I know there’s a lot to learn, but this team has everything I need to get there.”

Where things go for A.J. Allmendinger after the test is still a question mark, but he clearly relishes the chance to write another chapter in an open-wheel career that never reached its full potential.

“To come back to it, it'll be interesting to see if the IndyCar feels like really, really fast or if it feels really gripped up, I'm sure it'll feel gripped up, but just those little nuances. But, in the end, it's about going out there and challenging myself. Every time I get in a racecar I'm out there challenging myself and trying to live up to my own expectations. And I say that to make it to where I don't disregard everybody else because, yeah, I'm driving Roger Penske's racecar, that's important to me, what he thinks and the sponsors and everybody. So it's not like it doesn't matter to me what people think. So I'm never going to say that.

“But at the same point, I look at it like I challenge myself and I know that if I go out there and get in a racecar and live up to my expectations, everybody else's going to be happy because my expectations are higher than anybody else could ever put on me. Sometimes it's good, sometimes it's bad because sometimes I put too much pressure on myself but it's the way I am, it's the way I've always been and it's the way I’ll always be. It's just going back in that Indy car at Sebring; going out there and re-learning it and challenging myself that I can go out there and be fast in the thing. That's the whole point.”

Marshall Pruett is SPEED.com's Auto Racing Editor, covering IndyCar and sports cars. Now in his 27th year in the sport, Pruett was an open-wheel mechanic, engineer and manager before joining SPEED. He also contributes to RACER, Road & Track and Racecar Engineering. Follow him @MarshallPruett.