Crash.net is at Sepang in Malaysia for Friday's opening day of the 2019 Shakedown test.
MotoGP test riders Stefan Bradl (Honda), Michele Pirro (Ducati), Jonas Folger (Yamaha), Sylvain Guintoli (Suzuki), Mika Kallio (KTM) and Bradley Smith (Aprilia) are all expected on track for their respective manufacturers, alongside some factory Japanese Superbike Championship teams.
However, they will also be joined, for at least part of the three-day test, by six MotoGP race riders.
With the winter test ban ending on January 31, KTM and Aprilia - the manufacturers that benefit from technical concessions, including extra private testing - plan to send their race riders out for an early 2019 debut ahead of next week's official Sepang test.
New KTM test rider Dani Pedrosa is absent due to his recent collarbone injury, while Folger suffered an injury to the same bone while training in December.
The Shakedown test (which does not feature any official timing) runs from Friday to Sunday.
The official MotoGP test - featuring all race riders and official timing - will then be held at the same circuit from February 6-8.