The 5.5 km track located on the outskirts of Kuala Lumpur has been resurfaced, while the gradient of some its 15 corners has also been changed.
The tweaks have been carried out to make the track surface smoother, improve drainage and make the corners flow better.
Although the overall layout remains the same, the changes to the track could dramatically alter the grip it offers, the lines drivers take into corners and tyre degradation, which is always an issue in a race usually run in sweltering heat.
“It might be a completely different circuit,” said Button, who is making his 300th grand prix start this weekend and has driven at Sepang in all but its debut year in 1999.
“But we won’t know until tomorrow, probably get a bit of an understanding from watching GP2 and GP3.
“It’s very smooth from what I see,” added the McLaren driver, who also scored his first podium in Malaysia.
The Malaysian race, with its notoriously fickle weather, often throws up an upset and the changes to the circuit could create more drama.
Rosberg said getting the tyres dialled into the new surface would be the biggest challenge.
“It will be very different,” said the Mercedes driver who leads team mate Lewis Hamilton by eight points in the overall standings and will be gunning for his fourth straight win this weekend.
“We all need to adapt to the new asphalt, which we don’t know how it’s going to handle here.”
But for a rookie like Manor's Esteban Ocon, the alterations level the playing field a bit.
“I have been around on a track walk but it will be my first time on this track,” said the Frenchman, who will be competing in only his fourth grand prix. “So… I don’t know how it was before.”
(Editing by Pritha Sarkar)
