Christian Horner has said that he needs to examine Nico Rosberg's pole position lap more closely after the Mercedes Driver set a session best sector time, despite it being under yellow flag conditions at the time.

Red Bull team principal Horner's drivers Daniel Ricciardo and Max Verstappen missed out on a chance of pole position because of the yellow flags, and he can't understand why Rosberg was able to better his time in the conditions.

"One thing I couldn't understand which I need to check is Rosberg was behind Daniel, and managed to get a purple middle sector," said Horner. "I don't know if they had it cleared by the time he got there."

Horner's Mercedes counterpart Toto Wolff said that Rosberg lifted in the yellow flag area and the lap time should stand.

"[Rosberg] had a big lift into the yellow zone, lost quite some time," he said. "But then at the end the yellow zone was gone. It should be okay from our data."