Ricciardo had stepped away from a full-time race seat following the 2022 season, after he and McLaren agreed to part company in the wake of a frustrating two years.
While the Australian had initially considered moving to another team, in the end he felt a year helping out as Red Bull's third driver would be a better bet for him.
Red Bull plans to make use of Ricciardo for both reserve and testing duties throughout 2023, and for that it put him back in its simulator to get him back up to speed with the current car developments.
But, having observed his driving, Red Bull has revealed that Ricciardo had picked up some bad habits in his time away from the squad at Renault and McLaren.
Red Bull team principal Christian Horner said: "I think the problem is when you drive a car that obviously has its limitations, you adapt, and you try and adjust to extract the maximum out of that car.
"It was clear when he came back that he picked up some habits that we didn't recognise as the Daniel that had left us two or three years earlier.
"But having had time off over Christmas and so on, and a chance to reset, when he's come back and got into the 2023 work, he's hit the ground running. I think he likes the feel of the car in the virtual world, which seems to correlate well with what we're seeing in the actual world.
"I think he's desperate to get a run in the car at some point to validate that, but we're certainly seeing him getting back to being far more reminiscent of the Daniel that we knew."
Ricciardo is attending his first grand prix of the season in Australia this weekend and is entrenching himself as much as needed inside the Red Bull squad.
Horner added: "He's really throwing himself into it. Sitting in all the briefings, he's been working hard on the simulator as well in the UK doing some race support and some development work on that.
"Daniel's just a positive energy to have around and it's great to see him getting his mojo back, to see that big smile on his face and he lights up a room when he walks in.
"Hopefully, he'll rediscover his love for the sport. He'll do a bit of testing for us later in the year and we'll see how that goes for him. But I think it's a different experience.
"It must be very tough for him not being a race driver this weekend, but he's thrown himself in and is embracing this new role."
