Ricciardo ended the day 19th on the timesheets, more than a second away from the outright pace and four-tenths down on RB team-mate Yuki Tsunoda.
It was a sharp downturn from the opening hour of running when the Australian was 12th best – though a similar distance away from the front of the field.
Both Ricciardo and Tsunoda ran soft tyres early in Free Practice 2 which saw them rise up the order in the opening minutes.
However, with an improving track and others completing their qualifying simulations later, the eight-time race winner found himself shuffled well down the order.
“It was a session of two halves,” reflected Ricciardo.
“We had two sets of soft and the first set was actually, I’d say, really good, like, much more competitive.
“I guess not everyone had a soft, but I think we were looking better at that point in time – maybe seventh or something. We were in the fight, as they say.
“And then, the second set, I struggled a lot.
“Then you got the track getting better and everything and everyone improving, and I really struggled to improve.
“There was a bit of traffic and a few things, but honestly, that second set was a bit more of a mystery.”
Data suggests that, in comparison to Alonso, Ricciardo started his best Free Practice 2 lap with a lower top speed down the front straight.
He also had a much lower minimum speed through Turn 4, by an estimated 20km/h, a deficit he carried through to the Turn 8 complex, where he was also slower than the Aston Martin.
Curiously, Ricciardo did have better top speeds in other areas, with Alonso’s car clipping (recharging its battery) into Turn 13, Turn 16, and to a lesser extent the final corner.
However, the time loss from Turn 4 through to Turn 8 was key, as it is also where Ricciardo lost out to his own team-mate in Free Practice 2.
His best lap was set on a set of lightly used soft tyres, having completed three slow laps prior to his timed effort.
Having recorded his time, Ricciardo then pitted before emerging for a 12-lap race stint, lapping some five seconds than he had previously.
Ricciardo’s fastest single lap came on his 15th lap of the session. While slightly earlier than most, it was set in largely similar conditions to the bulk of the field.
Those who went faster banked their time on the first timed lap out of the pits, however.
Even with those known variables, the Australian was left confused.
“It was weird,” he said of the session.
“Sometimes a tyre doesn’t feel like it gives you what it should and it felt like it just never really gave me that, what we call that bite.
“I don’t want to just leave it to ‘Oh tomorrow we’ll just put a new set on, and it’ll be better’.
“Obviously, we’ll try to learn and understand if there was something that we could have done different.
“In any case, we’re going to go out there tomorrow and put some new sets on, and hopefully, they treat me a little better because we didn’t change too much with the car, so I don’t think we need to go crazy.
“I think putting the lap together, we’re more or less in that fight that we expect to be in.
“It’s such a different circuit to Bahrain and the surface and again, the way the tyres behave, it’s not obvious that they give you everything on the first lap,” he added.
“Qualifying could have quite a swing, and I’ll make sure I’m on the upswing, not the downswing.”