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. We have missed him by our side in Hockenheim and Hungary, and can't wait to have him back with us on the grand prix tracks of this world. The recovery he now faces is not a race. But knowing Niki, I'm sure he will soon be telling every nurse and doctor that he has had enough of the hospital.
"We wish him a safe and speedy recovery - in that order - and send all our positive energy to him and his family. I miss you my friend.''
Four-time champion Lewis Hamilton also took to Instagram to wish Lauda well.
"Sending you all my love, prayers and support, Niki. Wishing you a speedy recovery.''