McLaren have taken the penalty in Austria as they expect it to be one of their least competitive races.
They did not want to be punished at one of the next two races, the British and Hungarian Grands Prix, which they expect to better suit their car.
The McLaren chassis is relatively strong but Honda is struggling in its first season back in F1 since 2008 and its power unit is under-powered and unreliable.
The longer corners of Silverstone, McLaren's home race, and the twisty nature of the Hungaroring will help the car counterbalance some of the engine's deficiencies more effectively than at Austria's Red Bull Ring, which is predominantly short corners and long straights.
Spaniard Alonso, world champion in 2005 and 2006, expects more penalties as the season progresses.
"We have to sacrifice some weekends," said the 33-year-old. "This is one, and there are more to come, but if we learn things that will be very useful it's OK."
The team have already had a difficult weekend, with a series of reliability issues curtailing running in Friday practice with a new aerodynamic package being used by Alonso.
He said the new package, which features a shorter nose and revised front and rear wings, was promising but he needed more time to fully assess it.
ncG1vNJzZmivp6x7o67CZ5qopV%2BovbC%2B02idqKqdqrmifY5samtpYGeGeQ%3D%3D