Kimi Antonelli said on Thursday he would continue to run the new Mercedes car specification at this weekend's Singapore Grand Prix, but admitted it could be "a challenge" on the slow and twisty Marina Bay Circuit.
Mercedes introduced a new aerodynamic package at the high-speed Sepang track for last weekend's Bahrain Grand Prix in Malaysia, where Antonelli finished second behind the Red Bull of Max Verstappen.
But the city-centre street layout in nearby Singapore is a very different proposition, with a series of 90-degree corners and bumpy surfaces in the night race.
Antonelli's teammate George Russell, who starts from the back of the grid because of a penalty for taking a new power unit, will revert to the old package for Singapore to give the team a direct comparison of the two on the slower corners.
"It's going to be a good challenge for us drivers and the team," said Antonelli, acknowledging that the addition of a sprint race this year means there will only be one Friday practice session to get the set-up right.
"It's going to be a very important weekend because we are trying to understand the new package.
"It's going to be very challenging but I am looking forward to it."
Russell said the decision for him to run the old set-up, so Mercedes could split their specifications, was an easy one to make.
"There's no signs telling us the upgrade (in Sepang) was not working," said Russell.
"We know the car we had in Baku was the same car as we had in Budapest and Zandvoort," explained Russell.
"In Baku we were on pole by eight tenths, and in Budapest we were four tenths off the pace.
"This engine penalty this weekend has given us a good opportunity to roll back. It's a no-brainer. It's the car that I won in Baku with."