Serena Williams has ruled herself out of being baby Archie Harrison Mountbatten-Windsor's godmother.

Serena Williams

Serena Williams

The royal's mother, The Duchess of Sussex, made a surprise appearance at Wimbledon on Thursday (04.07.19) evening to support her friend, but speaking at a press conference that day, the tennis ace insisted she isn't one of the secret godparents Meghan and her husband, The Duke of Sussex, have chosen for their first born - who arrived into the world on May 6 - and pointed out that she will be on the court when the tot's christening takes place tomorrow at Windsor Castle (06.07.19).

She said: "No, I'm working on Saturday."

Meghan has always had a close friendship with Serena and the brunette beauty even watched the royal couple tie the knot at last year.

But, despite their strong bond, the 37-year-old sportswoman won't be dishing out any parenting advice to the happy couple any time soon - even though she has 19-month-old daughter Alexis Olympia with husband Alexis Ohanian.

She said recently: "I never pass on words of wisdom because I feel like for everyone - when they have a kid, especially when you just have a baby - it's so difficult to just be. It's just like, 'Get through the first three [or] four months and then we can talk.' "

Meghan and Harry have decided to break royal tradition and keep their son's godparents private.

A statement from Buckingham Palace read: "Archie Harrison Mountbatten-Windsor will be christened in a small private ceremony by the Archbishop of Canterbury in the Private Chapel at Windsor Castle on Saturday 6 July.

"The Duke and Duchess of Sussex look forward to sharing some images taken on the day by photographer Chris Allerton.

"The godparents, in keeping with their wishes, will remain private."