Ahead of Wimbledon, Serena Williams was surprised by Roger Federer's claims that she may well be the greatest player of all time (GOAT).

With 23 Grand Slams to her name, just one behind the record held by Margaret Court, Williams is certainly contender for the unofficial accolade and an eighth win at Wimbledon this month could cement it even further in many people's views.

Federer, a strong GOAT contender himself, is one who definitely believes the American has a case.

"[Williams’ career] has been fascinating to watch," Federer revealed in an interview in May. "She had a totally different upbringing — I came up through Switzerland with the federation, she did it with her dad and her sister."

"It’s an amazing story unto itself — and then she became one of the greatest, if not the greatest tennis player of all time," Federer said, adding he was talking about the overall best, regardless of gender.

Roger Federer and Serena Williams
Could 2018 be another year where Roger Federer and Serena Williams both emerge triumphant at Wimbledon? In this picture, Switzerland's Federer (L) and Williams of United States posing for pictures with their respective Wimbledon winners trophies at the Champions Dinner in London, July 9, 2012. TOM LOVELOCK/AFP/GettyImages

When asked about Federer's view during her pre-Wimbledon press conference, Williams admitted she did not expect those comments, but would return the favor by labeling the Swiss legend, who boasts 20 Grand Slam titles and 98 career singles titles, as the greatest player.

"Honestly, I was surprised," Williams responded. "I feel the same way about him. I think he’s clearly, you know, the greatest player. I mean, if you go by numbers, it’s men’s and women’s, it’s different. … But I always try to get rid of those, the stigma of men and women. I just feel like he’s such a great player and also an incredible, humble human being, which obviously shows. It continues to show throughout the years."

Williams will be taking part at Wimbledon for the first time since she won it in 2016, and following her maternity leave last year, will be seeded for the event after many in the tennis world called for it. She was previously using her protected No. 1 ranking that allowed her to enter tournaments but remained unseeded in the three events she played so far this year.

The 36-year-old will be given the 25th seed now though, and while she might have wanted a higher seed, she was grateful to receive a seeding in the first place.

"I think I would be very ungrateful if I sat here and said it [the seeding] was too low, to be honest," she added. "So not at all. I don’t at all feel that way. In fact, I was pleasantly surprised. I came in here expecting that maybe I wouldn’t get a seed."

"I do know Wimbledon tends to kind of beat to their own drum. That’s kind of one thing that’s been able to set them apart. It was a little bit in the back of my mind, that I would have a chance, but I didn’t put that on it. You know, I’m here to do the best that I can do. I thought it was very, very noble and honest and cool. Maybe not honest, but cool. I don’t know where 'honest' came from."

Williams will begin her Wimbledon campaign against Arantxa Rus while Federer will look to retain his crown by defeating Serbia's Dusan Lajovic. Both matches take place Monday.