Unwell Marc Marquez went downhill after first Malaysian GP practice

Marquez travelled to Indonesia earlier this week, between the Australian and Malaysian GPs, and revealed on Thursday that he had started to feel unwell on Wednesday.

With what has now been outlined as gastroenteritis, Marquez managed to set the fastest time on Friday morning at Sepang, which remained the best of the day after rain fell before the second session.

His condition worsened afterwards, and Marquez decided there was not enough to be gained from riding in practice two, instead turning his attention to recovering for the balance of the weekend.

"In the morning I didn't feel very well - I've had gastroenteritis for the last two days - but I was able to go out and ride even though I was not at 100%," he said.

"After the session and the effort I put in, I began feeling worse, because gastroenteritis also dehydrates you.

"Looking at the track conditions, we decided not to go out.

"Tomorrow we'll try to improve and I think it has been good for me not go out there, and to instead save myself for Saturday and especially Sunday."

Marquez was not the only rider to sit out second practice, with Ducati's Andrea Iannone doing the same on his return from a fractured vertebra.

Iannone fractured the T3 in his upper back at Misano seven weeks ago, and other than lapping at Aragon a fortnight later in a bid to come back there, has been out of action.

The Italian completed 17 laps in the morning and set the fourth-fastest time, 0.311 seconds off Marquez's benchmark.

"It was a positive return," he said.

"I expected to struggle a lot more, not really physically but in general in getting back up to speed, but already in the first practice session I had an excellent feeling with my bike and was feeling good.

"So in the end I am pleased with how this first day went after my long period away from the track.

"This afternoon we opted not to go out in the wet so as to avoid taking any unnecessary risks, but obviously if it continues to rain tomorrow we will start to get ready in case the race on Sunday is a wet one."