Max Verstappen will serve a 15-place grid penalty in Canada after Toro Rosso changed his engine on Saturday morning.
Verstappen came into the weekend already knowing he would drop five places on the grid as part of his punishment for colliding with Romain Grosjean in Monaco. Toro Rosso has had a number of reliability gremlins this year with Renault and Saturday's change saw Verstappen move on to his fifth power unit of the season - only four are allowed per driver this year before penalties are incurred.
Last year grid penalties carried over to the next race if they went unserved, but that no longer applies under the 2015 regulations. Instead, any part of the grid penalty Verstappen is unable to serve in Montreal will be converted into a time penalty.
Unserved grid places will be converted as follows:
1-5 places: 5s penalty (to final race time)
6-10 places: 10s penalty (to final race time)
11+ places: Drive-through penalty
Verstappen becomes the first driver to move on to a fifth power unit in 2015. Daniel Ricciardo and Daniil Kvyat are both on their fourth power unit this weekend, though Red Bull hopes to avoid incurring a penalty at this weekend's race.