Stoffel Vandoorne and Lando Norris will lead McLaren's running in the two-day test after the Spanish Grand Prix.
Formula 1 teams will remain at the Circuit de Barcelona-Catalunya for two days of on-track action after the race to go through a series of testing programmes and learn more about their 2018 challengers.
The Belgian driver will head-up running on the first day of the testing in the MCL33 on Tuesday 15 May, before Norris takes over on Wednesday 16.
McLaren will be running a second car on both days of the test in conjunction with Pirelli to conduct a series of tyre tests; Norris will run on the first day while long-time test driver Oliver Turvey will complete the final day of running.
F2 championship leader Norris already has some experience with F1 machinery after he completed running for McLaren in Hungary and Abu Dhabi last year.
The Woking-based team has enjoyed a much better start to the 2018 campaign than in previous years, picking up 36 points from the first four races; the team had only managed 30 points through the whole of 2017.
McLaren currently lies fourth in the Constructors' Championship, a point ahead of Renault.
