Mercedes boss Toto Wolff has wished Niki Lauda a safe and speedy recovery following his lung surgery on Thursday.
Lauda -- who has been Mercedes' non-executive chairman since 2012 -- had an operation in Vienna earlier in the week.
''Although we should enjoy the start of our summer holidays this evening, none of us at Mercedes will pretend that we feel happy - our thoughts are rather with Niki, Birgit and the Lauda family,'' Wolff said. "The world knows Niki as an Formula One legend with incredible power and resilience.
''For all of us at Mercedes he is our chairman, our mentor and our friend.