Valtteri Bottas says he drove "without any pain" during practice at Sepang on Friday and is confident he won't have issues for the rest of the weekend.
The Williams driver was forced to watch the Australian Grand Prix from the sidelines after he injured his back during Q2 in Melbourne last time out.
However, he has undergone different treatments ahead of this weekend's Malaysian GP and was given the green light by the FIA medical delegate to take part in the race.
After spending plenty of time in the FW37 during the two practice sessions on Friday, the Finn declared that his back won't give him any problems.
"The changes we have made to my driving position have been positive and it was nice to be able to drive without any pain," he said. "I am confident for the rest of the weekend that I won’t be troubled by my back."
Bottas was eighth fastest in FP1 and then moved up to fifth later in the afternoon.
"The track in the morning was really dirty with a lot of dust which will change throughout the weekend and the second session was very hot," he said. "The short runs were good but the car had some damage to a rear brake duct in the long runs so it is hard to give any accurate feedback."