Although Ricciardo was faster in his regular Toro Rosso in the morning than in the Red Bull, and also had a spin during his half-day 'audition' for the champion team, he had no concerns that he could have squandered his opportunity to shine.
"I think I drove to my ability and did what I could," said Ricciardo, who is going up against Kimi Raikkonen for the seat alongside Sebastian Vettel.
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"It was a bit tricky with Pirelli and the circumstances [of the test], as we were not really allowed to adjust the car. Ideally you would like to make some mechanical changes and set the car up for the conditions; but it is going to be the same for all the other guys.
"It was a good opportunity to get behind the wheel and experience two different beasts."
'ENJOYMENT NOT PRESSURE'
Although media attention was on Ricciardo's progress over the day - with his Toro Rosso lap setting the benchmark - he insisted he did not feel any undue pressure to perform at this crucial moment in his career.
"It was just fun. Just excitement," he explained. "It is nice to get the opportunity to drive the car and I definitely treated it as something more of excitement than a pressure.
"It was exciting. I think I did what I could. Let's see what happens."
Ricciardo said he would now keep an eye on Vettel's performance in the car on Friday, as matters were now pretty much out of his hand.
"We will see what happens. It is not my decision. I've still got the season ahead with Toro Rosso.
"The last few races have been better so we need to keep continuing like that, and I think this test is something for them, for Red Bull, to look at.
"But there is still the rest of the season to observe. I wouldn't get too caught up in today; I need to switch back my focus to Toro Rosso."
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He added: "It was nice to get a few laps in the [Red Bull] car as testing is pretty limited.
"If I don't get the chance, further down the track, that was already a nice little bonus. We will see what happens. I will watch Seb's times tomorrow and hopefully he won't put me to shame."
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