First attempt
De Villiers won the Dakar Rally back in 2009 and has taken several podium finishes with Toyota since that memorable victory.
This will be the South African's first attempt at the Qatar event in his Toyota GAZOO Racing South Africa Hilux with navigator Robert Howie.
Costly retirement
Domzala suffered a costly retirement at the opening round in Russia after rolling his Toyota Hilux and the Pole missed both the Dubai International Baja and the Abu Dhabi Desert Challenge.
Pointless after three rounds, last year's Baja Russia winner will be hoping to kick-start his season in Qatar with fellow countryman Maciej Marton reading the road book.
Eyeing podium
Saudi Arabia's Yasir began the season strongly with fifth place in Russia and third in Dubai, but a mechanical issue at the Abu Dhabi Desert Challenge cost him a potential top five finish and valuable championship points.
He currently holds fifth in the Drivers' Championship - four points behind Al Attiyah - and he and Russian co-driver Alexei Kuzmich will be hoping for a podium finish in Qatar.
Experienced Dutchman
The experienced Dutchman Van Loon is planning to tackle the Dakar Rally again in 2019 and has entered the Qatar event to begin his preparations for another South American adventure.
He and co-driver Wouter Rosegaar finished sixth in Qatar last year and will be hoping to improve on that result on this occasion.