Incredibly, Mabbutt has made more than 3,000 phone calls to supporters who have been isolating.
"Over the last 16 months, I’ve spent two hours a day speaking to fans from the age of 70 to 95," the club ambassador told Spurs' official website.
"By just talking to someone for a few minutes a day, you get a good understanding of whether they are in good spirits or struggling.
"Spurs have been a part of my family for 39 years, so it was great to be able to do something."
In recognition of his remarkable show of support, Spurs surprised Mabbutt with a selection of thank-you videos from the grateful fans he had rung.
"You made a phone call to me in January when I was COVID positive," said Ray Gates. "It was a massive pick-me-up to hear your voice and have a chat about the club."
For Graham Sharp, Mabbutt's call was the perfect surprise birthday present.
“It was a real pleasure to receive Gary’s call on my 75th birthday," he explained. "He was so generous with his time, and I will never forget his kindness."
Apart from his 3,000+ calls Mabbutt and Spurs have continued to show their support for the NHS in other ways.
Tottenham Hotspur Stadium has been used as a drive-through testing centre, while North Middlesex University Hospital has also used the facility to relocate its Women’s Outpatient Services.
Mabbutt recently joined hospital staff on the NHS's 73rd anniversary while the club's stadium was illuminated blue to celebrate the occasion.