As Ricciardo prepares for his F1 comeback at this weekend's Hungarian Grand Prix, the Australian is well aware that he is going to face a pretty challenging time in an AlphaTauri car that has left the team at the bottom of the constructors' championship standings.
But reflecting on the reasons why Ricciardo has elected to throw himself in at the deep end as a replacement for Nyck de Vries, Red Bull team principal Horner has explained that there is a bigger picture at play.
He says Ricciardo is clearly out to prove himself as the best candidate to land a seat at Red Bull for 2025 when current driver Perez will be out of contract.
Speaking to the F1 Nation podcast, Horner denied suggestions that Ricciardo was being evaluated for a Red Bull seat in 2024 but said everything was about the following year.
"At the moment, there's only something in place until the end of the season, so there are no thoughts or expectations beyond that," said Horner. "We've loaned him to AlphaTauri until the end of the year.
"Obviously, our drivers are going to be Max [Verstappen] and Checo again next year, but it's always good to have talent in reserve. And I think Daniel is viewing AlphaTauri, he firmly wants to be pitching for that 2025 Red Bull seat.
"That is his goal and objective and, by going to AlphaTauri, I think he sees that as his best route of stating his case for 2025."
Horner explained that the decision to hand Ricciardo the AlphaTauri seat for the rest of the season was made pretty quickly during last week's Silverstone tyre test, when the Australian had his first outing in Red Bull's RB19 car.
When he delivered a time that, when adjusted based on fuel, tyre and track conditions, would have been good enough to secure a spot on the front row for the British Grand Prix, Horner said the decision was effectively made.
"What impressed me the most, and I went up to have a look at the test, was bearing in mind he hasn't driven this car and hadn't been in a car for seven months, within his third or fourth lap he was down to a time that was within a second of what our drivers were achieving," revealed Horner.
"Then his first proper run, as it were, on tyres that were comparable, you could see his confidence was growing and growing.
"That first [flying] lap of probably what was his seventh lap of the day would have put him on the front of the grid. So it was hugely impressive."
Although Ricciardo may face some struggles in the tricky AlphaTauri, Horner said that there had been no reluctance shown about taking on the challenge when it became clear that a replacement for de Vries was needed.
"First of all, we had to be clear that did he want to do it?" added Horner. "Stepping into an AlphaTauri is very different to driving a Red Bull Car.
"It will certainly have its challenges and I think that thing that we needed to be sure of was he up for that challenge of scrapping to get out of Q1? And he seemed more than happy to go back into that situation, to get back on the grid and be an F1 driver again."
Horner explained that it would have been "unfair" to put a rookie like Liam Lawson into the seat rather than someone as experienced as Ricciardo, as he opened up on why he felt de Vries had not delivered what had been hoped.
"It was becoming obviously a difficult situation for Nyck de Vries because there was a high expectation on him, because whilst inexperienced in F1, he's obviously a very experienced driver," he said.
"I think that there was a general feeling that Nyck wasn't quite hitting the mark."
He added: "I think that Nyck is a very capable driver and a FE champion and an F2 champion, but he's obviously got a lot of experience. He's not a young driver as such from an age perspective. And I just didn't see how it fitted within the junior programme. It was always a stop gap."
Asked if Red Bull should have waited until after de Vries' home race at Zandvoort, Horner said: "I think it's very difficult to do that.
"It would have meant obviously leaving him in the car until after the summer break. I think the situation was clear.
"It was a question of okay, what's the point of waiting? If we are going to do something we might as well get on with it and give Daniel 12 races to see what he's capable of."
