McLaren has postponed protege Stoffel Vandoorne's Formula 1 test debut and will keep Kevin Magnussen in the car for this week's Bahrain test.
Although the team's original intention had been to give GP2 driver Vandoorne his maiden F1 run and to use test driver Oliver Turvey on the other day of the first of 2014's post-race tests, AUTOSPORT understands that McLaren decided it was important to have driver continuity across the Bahrain and Chinese Grands Prix and the test.
Jenson Button was also offered the opportunity to run, but was content to leave both days in Magnussen's hands.
The test commenced on Tuesday morning. Sauber is giving development driver Sergey Sirotkin a day of running so he can get his Superlicence, while Williams and Caterham are also using test drivers in the form of Felipe Nasr and Robin Frijns respectively.
Caterham is carrying out its day of Pirelli tyre testing on day one, with McLaren and Williams then fulfilling that role on Wednesday.
All 11 teams are required to dedicate a day of in-season testing to Pirelli work during the course of 2014.
The Bahrain test is the first of four scheduled for this year as the testing ban is relaxed amid this season's comprehensive technical rule changes. Further sessions are scheduled for after the Spanish, British and Abu Dhabi Grands Prix.
Bahrain test line-up: Tuesday Wednesday Red Bull Daniel Ricciardo Daniel Ricciardo Mercedes Nico Rosberg Lewis Hamilton Ferrari Fernando Alonso Fernando Alonso Lotus Pastor Maldonado Romain Grosjean McLaren Kevin Magnussen Kevin Magnussen Force India Nico Hulkenberg Sergio Perez Sauber Sergey Sirotkin Giedo van der Garde Toro Rosso Daniil Kvyat Jean-Eric Vergne Williams Valtteri Bottas Felipe Nasr Marussia Max Chilton Jules Bianchi Caterham Robin Frijns Marcus Ericsson