Stoffel Vandoorne is set to take a grid penalty for Formula 1's Russian Grand Prix, after McLaren-Honda suffered more engine reliability problems in first practice.
McLaren endured a catalogue of reliability trouble with Honda's MGU-H in Bahrain, so Vandoorne and team-mate Fernando Alonso both received updated MGU-Hs for this weekend's race.
Honda detected a suspected problem with the MGU-K on Vandoorne's car at the end of the first practice session, so will need to fit his car with a replacement unit.
Because there is not enough time between sessions to swap the individual components of the power unit, Honda will change the entire engine on Vandoorne's car, save for the battery and control electronics.
The replacement engine will also feature Honda's new specification of MGU-H, which contains countermeasures developed following the post-Bahrain Grand Prix test, in which Vandoorne completed 81 laps untroubled on the final day.
The engine swap will push Vandoorne over the FIA's limit for engine component use through a season, taking him to his fifth MGU-H and fifth turbocharger of 2017 before the fourth race of the season has even begun.
That will translate to a grid penalty of 15 places for Sunday's race.
A Honda statement said: "Suspected MGU-K issue with Stoffel's PU in FP1. The issue is under investigation.
"In the interest of time we opted to change PU. We hope to be back out on track during FP2.
"The MGU-H/TC will be Stoffel's fifth, which means he will receive 15 grid penalties for the race."