Sainz ran second quickest in the pole position shootout, falling only 0.044sec short of team-mate Charles Leclerc as Max Verstappen abandoned his final flying lap to end up third.
But Sainz must fight back from 12th on the grid as a legacy of taking a third control electronics package of the season to exceed the allocated two. For this, the stewards reluctantly handed out a 10-place grid penalty.
The reprimand keeps Sainz in a "very bad mood". He said: "An outstanding job by the whole team. We've dominated qualifying together after a tough Friday yesterday to put together the whole car again.
"To get a front-row lock-out, I think it's incredible. Obviously, I would love to be on pole because it would mean I start 11th instead of 12. But I think that we did the maximum that we could today.
"Obviously still disappointed with yesterday. I'm not going to lie. I'm still in a very bad mood but I'm trying not to show it too much. But it is what it is."
The upset and repairs are owed to extensive damage from Sainz hitting a loose water valve cover after only nine minutes of FP1 causing the session to be cancelled and FP2 delayed by 2hours30mins.
Given the damage was not the fault of the competitor, the stewards studied the rules to look for an escape clause.
But they ultimately concluded: "If they had the authority to grant a derogation in what they consider in this case to be mitigating, unusual and unfortunate circumstances, they would have done so, however, the regulations do not allow such action."
Hit with the drop, Sainz reckoned he was now in "comeback mode".
He continued: "[My race] depends obviously how the start goes, how the graining on the tyres is and then how easy it is to overtake.
"I think that the pace, it clearly looks like we have it this weekend.
"I would love to be fighting for the win tomorrow with Charles and Max, but unfortunately, I'm going to be on a comeback mode, a comeback race.
"Hopefully I can get to the front at some point. But I think it's going to be tricky."
