Red Bull dominated the practice sessions by putting both the cars at the top in FP 2 but Sebastian Vettel, who had the fastest time, reckons that the qualifying result may be different.
After the final practice session on Saturday, the drivers will fight for the positions on the grid for Sunday's race.
"Friday's are always difficult with so many things changing. The track improvement was quite big today, it was dusty to start and improved lap by lap, so I wouldn't be surprised if tomorrow the order is different, but we've had worse Fridays, so I am happy. We need to keep working and improve a little bit overnight," Vettel the defending champion said.
His team-mate Mark Webber, whose late charge saw him shoot up to second position, said they have good information for the race.
"That went pretty well. I had a lock-up in Turn 1, which I could have done without, but it isn't the end of the world. We got on with the important stuff, which is understanding the soft tyre on short and long runs. We'll have a look where we can improve the car, you can always improve. The team is incredibly motivated and the drivers also," the Australian said.
Ferrari's Alonso, who was behind the two Red Bull cars, the FP2 was "difficult" after a good morning session.
"In the second one, when we switched from the Hard to Soft, the balance of the car was no longer the best and it was becoming very difficult to drive, to such an extent that I ended up spinning. Unfortunately, that damaged a tyre and so I was unable to do the work over a long run which had been one of our priorities," the Spaniard said.