UPDATE: Alvaro Bautista will replace Lorenzo at Phillip Island.

Jorge Lorenzo will miss next weekend's Australian MotoGP, Ducati has confirmed.

A tweet from the team stated that the injured triple MotoGP champion: "Will return home today in order to have further checks with doctors and speed up the recovery of his left wrist. Jorge will miss the Australian GP next week and will try to be as fit as possible for the Malaysian GP."

Ducati say they are yet to decide on the replacement rider to join Andrea Dovizioso for Phillip Island... But it will not be Casey Stoner.

The substitute decision is complicated by test rider Michele Pirro apparently being busy and MotoGP rules clamping down on existing riders switching teams as a replacement, due to the potential to dodge the engine-change limits, "unless approved by the GPC":

Substitute and Replacement Riders - Effective Immediately (September 8, 2018)
Concern has been expressed that MotoGP class teams could manipulate the current regulation to switch machines within the same team, or with another team, and perhaps help a rider who was close to exceeding his engine allocation. Because there are so many possible scenarios the regulations will be modified so that a substitute or replacement rider cannot be a rider currently contracted to the Championship unless approved by the GPC [Grand Prix Commision].

Given that Xavier Simeon has switched from GP16 machines to the GP17s of injured Avintia team-mate Tito Rabat from Misano onwards, the GPC may be flexible about a satellite Ducati rider replacing Lorenzo, since the motive would clearly not be engine-allocation related.

Home Australian star Jack Miller moving over from Pramac would be a popular choice, although another rider would then need to be found to take over Miller's satellite GP17 seat... All current WorldSBK riders will be competing at the Qatar finale next weekend.

Lorenzo's Phillip Island withdraw was widely expected, after pulling out of this weekend's Motegi round when he discovered that the wrist fracture from Thailand was worst than expected during a brief track return on Friday morning.

The Malaysian Grand Prix, which should be Lorenzo's penultimate appearance for Ducati before moving to Repsol Honda, takes place from November 2-4.

Lorenzo, who is currently fifth in the world championship after non-scores at the last three rounds (including today's Japanese MotoGP), is due to make his RCV debut at the Valencia post-race test from November 20-21.