Button, 43, is driving the No. 15 Rick Ware Racing Ford Mustang with support from Stewart-Haas Racing.
In the only 50-minute practice session this weekend, he ran 13 total laps and went 28th quickest out of 39 entries. He was 1.770s off pace-setter Tyler Reddick, but ahead of fellow F1 World Champion Kimi Raikkonen by about half a second.
His steep learning curve began even before exiting the Cup Series garage.
“I mean first of all ... A little bit anxious but excited at the same time," he admitted during a Friday press conference at the track. "I forgot how to start the car which was interesting. So they pushed the car back, and I’m like ‘It won’t start.’ There were a few other switches I had to put up. But then it was okay.
"I got onto the circuit and I was surprised by how little grip there was initially when I pulled away and the tires were cold. But, it comes to you over time. The gear shifting is something that ... I’ve not never driven a sequential gearbox car. I’ve never pulled back going through the gears and pushed to go down. It’s something completely new to learn. I’ve driven a manual gearbox, but you always go across the box. The last time I drove a gearbox like this was like in 1999. There’s a lot that you go back into the bank of info you’ve learned over the years, and you bring it out again. It comes to you pretty quick. I really enjoyed it."
Button also noted how unique of an experience it was for him to have a spotter guiding him throughout the session: "It’s also interesting having spotters. I’ve never had spotters before. So, I’ve got guys in my ear the whole way around telling me there’s traffic behind, there’s traffic in front – it’s quite soothing. I kind of like it. Our spotters have very soothing voices, which I think is good and it’s especially going to be good on Sunday when it’s manic out there. That’s something else to learn – having my mirrors, so I can see around me. But they tell me all the fun information about what’s going on around me.”
He later added: "As I noticed here in practice, people don’t move out of the way when they’re on a slow lap and you’re on a quick lap. There’s a lot to learn. It’s a very, very different sports than what I’m used to."
COTA is the first of three planned Cup starts this year for Button. He will also race at the Chicago Street Course on July 2nd and at the Indianapolis Road Course on August 13th.
Although he wasn't very quick in practice, he remains excited about the challenge at hand. He hopes for a solid weekend overall and to improve with every lap of competition.
"I get to race against 30 other crazy guys out there," he said. "I’m really, really looking forward to the challenge – and it definitely is a big challenge. Jumping in the car for a 50-minute practice session – and that’s it – before we go qualifying and racing. It’s tough I think for anyone who is not used to big, heavy cars with low downforce. I’m enjoying the process. The team has been great, and I’m looking forward to a good, solid weekend. The car felt pretty good out there, and I think tomorrow in qualifying – when it really counts to get a lap in – there’s a bit more pressure. We’ll see how it goes. Setup wise working with my guys, improving it.
"Yeah, we’re going in the right direction.”
UPDATE: Button qualified 24th for Sunday's race, starting alongside Justin Haley on Row 12. Raikkonen is just ahead in Row 11, starting 22nd.