Lewis Hamilton has revealed he spoke to Mercedes team chairman Niki Lauda earlier this week.
F1 legend Lauda has been in intensive care for over two months following a lung transplant.
"He called me two days ago. I was shocked to hear from him," Hamilton told Austria's O3 radio.
"I said 'You sound younger than ever'. He's very determined to come back and grateful to the doctors for their good work and to his wife," the championship leader added.
"He said he should be released from intensive care soon and then I can visit him. For sure I'll be in Vienna before the end of the season," Hamilton added.
"We miss him here in the team but we have his spirit at the races with us."