Wimbledon champions Roger Federer and Serena Williams have joined in the call for technology to be introduced into football in the wake of the furore caused by England's disallowed World Cup goal against Germany.
Federer, who is a well-known critic of the use of electronic officiating in tennis, described the decision to disallow Frank Lampard's goal as "incredible", while Williams dubbed it "outrageous" and "unbelievable".
"I don't know if I can be a genuine fan of football because of the calls," said Williams. "I mean, the call with the England game was outrageous.
"Humans can't be perfect, which is why there is technology. I don't understand how, in this day and age, they don't have better technology.
"It could have been a totally different game if it was 2-2 - unbelievable!"
Federer feels the incident highlighted the "need for a change", arguing that there is a stronger argument for using modern technology in football than in tennis.
"We have electronic line calling even though we don't need it," he said. "They should have it and they don't. So it's a choice the guys have to make at the top.
"I do struggle a little bit with soccer at times because there's so many mistakes.
"Don't blame them (the officials). They're so far away sometimes from what's happening and then also so many goals are disallowed that are goals and others are not counted that would be goals. It's frustrating as a fan.
"You just hope that all those things go for you when you're in this kind of a stage of a tournament. They could have been sent home just because of that single mistake and it's incredible.
"I think it's rough. To me it seems like it's just crying for a change."
While Federer maintained his opposition to the challenge system in tennis, Williams spoke out in favour.
"In tennis, I think it's good for the fans, so I like it," she said. "I don't really use it too much but I think it's cool."