The Phillip Island MotoGP race has been cut to just 19 laps after further tire issues.

MotoGP had already instituted mandatory mid-race pitstops to change onto bikes with fresh tires after Bridgestone expressed concern that its rubber would not last more than 14 of the 27 scheduled laps.

Following the warm-up the format was revised again, with 19 laps the new distance and pit stops required after nine or 10 laps.

If rain comes, the race will be red-flagged so that riders can change onto bikes with wet tires.