Gatland fractured both heels during a fall at his house in Waikato in April, delaying his appointment to lead next year's tour to Australia.
The Lions insist the surgery is part of the 49-year-old New Zealander's rehabilitation programme.
"The operation to his right heel, which was broken in his much documented accident, will see Warren enter hospital on Friday," read a statement released by the Lions.
"The procedure will entail treatment to an area of damaged and blistered skin.
"It is expected he will spend a few days in hospital after the procedure."
Gatland was appointed Lions coach three weeks ago having led Wales to the semi-finals of the World Cup and then a second Six Nations Grand Slam in four years.
It was initially feared that his accident in Waikato might threaten his involvement with the Lions, with assistant Rob Howley taking charge for Wales' summer series against the Wallabies.
But those concerns eased with his recovery and next summer Gatland will aim to mastermind the Lions' first Test series win in 16 years.