Honda have provided Red Bull and AlphaTauri with new engines this weekend in France, with Christian Horner admitting he was surprised to see Mercedes make their changes in Azerbaijan.
Max Verstappen, Sergio Perez and Pierre Gasly will all have new engines this weekend, while Yuki Tsunoda is out of sync in that regard given his second unit was installed following his heavy crash during qualifying for the Emilia Romagna Grand Prix. Mercedes made its changes, as well as for its customer teams, back in Baku which caught the attention of Horner.
"It was surprising to see Mercedes changed so early," Horner told Sky Sports. "We've not seen that in recent years, they've usually been the longest. Whether they've got little more degradation than they expected, I don't know.
Regardless of Mercedes' approach, Red Bull are sticking to their plan even if they aren't sure how many races there will be in 2021.
"We're just sort of running to our plan," Horner added. "The difficult thing to predict at the moment is just how many races are we going to have in the season."