The Australian split his duties on Thursday, lapping in his regular Toro Rosso in the morning, before switching to Red Bull in the afternoon as the team decide whether to hand him the chance to replace Mark Webber next season.
His best time of one minute 32.972 seconds came during the morning, and his afternoon pace in the Red Bull was only enough for the third best time.
The 24-year-old also suffered the embarrassment of running off track just a handful of laps into his running with the senior team.
Ricciardo's times were split by Carlos Sainz Jr on his first run in a Formula One car, the Spaniard having taken over the Toro Rosso in the afternoon.
Davide Valsecchi was fourth for Lotus, with Oliver Turvey fifth for McLaren.
GP2 racer James Calado did another solid job for Force India with the sixth-fastest time.
Paul di Resta ended the day 14th out of 15.
"It was good today but very busy, so it's still a bit of a blur," said Ricciardo.
"I did quite a few laps this afternoon [Thursday], so I'm happy with that. I had a small off but otherwise it was a trouble-free day. The off was my mistake, I just lost the rear on the entry.
"It was a good opportunity to get behind the wheel and experience two different beasts today [Thursday].
"In terms of the inevitable speculation, I think this test is something for Red Bull to look at, but there's still the rest of the season with Toro Rosso to do, so I'll switch my focus back to that and won't get too caught up in any rumours."
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