Update: The 2023 factory Aprilia has sprouted some new front wings, hanging down from the fork (see below). A new aero device was also spotted attached to the RS-GP's swingarm as well as a revised version of the rear set aero.

As of midday, reigning world champion Francesco Bagnaia was fastest from fellow Ducati rider Jorge Martin, with home hero Miguel Oliveira in third for RNF Aprilia.

The two-day Algarve outing is the last chance for teams and riders to gather data before engine spec is locked for the 2023 season.

Aerodynamics also have to be decided upon, with only one update allowed during the world championship campaign.

A selection of pictures from the opening morning can be seen below...

Is 2023 Make or BREAK for Yamaha? | Crash MotoGP Podcast EP.79

Francesco Bagnaia was fastest as of midday.

VR46 Ducati's Luca Marini, fastest in both previous winter tests, has also featured at the top of the timesheets.

New RNF Aprilia rider and home star Miguel Oliveira has been among the fastest of the non-Ducatis.

Fabio Quartararo's new Yamaha is again showing impressive top speed, but it remains to be seen if the 'qualifying lap' woes from Sepang have been solved.

Marc Marquez trying a black front fairing on his Repsol Honda.

Brad Binder was fastest of the KTMs in the early running, but all the RC16s were in the lower half of the timesheet.