But the latest series of the sporting quiz show has seen viewing figures plummet to just 850,000.
One episode which aired on on August 19 saw a record low of just 730,000 viewers tune in - less than those who watched Channel 5 documentary Britain's Poshest Farm Shops.
Watch: Sue Barker bids farewell to Wimbledon
When Barker chaired the quiz - with team captains ex-cricketer Phil Tufnell and former rugby player Matt Dawson - Question Of Sport achieved an average audience of between four and five million.
But McGuinness' first series at the helm - with ex-hockey player Sam Quek and former rugby pro Ugo Monye as team captains - managed just 2.2 million viewers.
The revelation that viewers are turning off since Baker's departure comes after she spoke out about her sacking by the BBC.
The 66-year-old TV presenter revealed the corporation tried to make her lie and claim the decision was her own, which she felt was disrespectful and upsetting.
In her new book Calling The Shots she said: "After 24 years in the hotseat, I was sacked as the host of A Question Of Sport - and I'm afraid that has left me slightly damaged.
"I had no problem with being replaced. It was the way it was handled. It taught me there is actually no way of leaving a role in a nice, pleasant and helpful manner, with your head held high."
Barker began hosting the BBC sports quiz show in 1997 and left in 2021.
A Question Of Sport began in 1968 and at its peak was watched by 19 million people - who tuned in to watch Princess Anne take part in the quiz in February 1987.
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