Red Bull have gotten off to their strongest start to a Formula 1 season in some time in 2021, just missing out on victory at the season opener in Bahrain before sealing a dominant win with Max Verstappen at the Emilia Romagna Grand Prix in Imola.
Verstappen won the race in Imola by 22 seconds ahead of Sir Lewis Hamilton in the Mercedes, and it could have been worse for the reigning champion if a red flag brought about by a collision between his teammate Valtteri Bottas and George Russell hadn't allowed him to unlap himself.
However, Red Bull team principal Christian Horner has warned that the coming double header of races in Portugal and Spain will provide the acid test for the Milton Keynes-based outfit's title charge as the tracks are more suited for Mercedes, he said in a column.
"We are now going into a double-header as the races come thick and fast. We go to Portugal and then Spain and they are both great tracks but circuits we would expect to play to Mercedes' strengths, based on last year's data," he said.
"Portimao was a good addition to the calendar last year, the surface will hopefully have weathered-in a little bit as the newly resurfaced circuit was very slippery. Barcelona is the benchmark we all have so much data from so it will be interesting to see who comes out on top.
"I am excited for both races and you can be sure that we are full of energy and motivation. If we can put Mercedes under a little bit of pressure at these tracks then that bodes well for the rest of the year. I always said it would take four races to get a clear picture of form, so now is the acid test."