Nick Kyrgios will be one of the biggest names in the draw at this year's Wimbledon, with the Australian star returning to SW19 following his final defeat to Novak Djokovic last year.
The 28-year-old stole the headlines in last year's tournament, with his antics drawing ire from the crowd as his underarm serve was branded 'disrespectful'. In addition, he admitted to having spat in the direction of a fan after his first-round win at the tournament
However, thanks to his mercurial talent on display during the most impressive Grand Slam performance of his career, Kyrgios became a star of the tournament, with his natural flair and imposing style winning over the British public. Debate around the use of underarm serves remains however, with some branding the move as unsporting, despite there being no rule on how the ball must be served.
Last year, Sir Andy Murray, one of the most popular players in Wimbledon history, used the same move to demonstrate its legitimacy in his second round win against Australia's James Duckworth, amid intense criticism of Kyrgios.
"He changed his return position. That's why I did it," Murray said when explaining his reason for using the underarm serve. "He was standing very close to return. He was struggling a little bit on the first-serve return, so he stepped probably two meters further back. As soon as I saw him step further back, I threw the underarm serve in.
"I personally have no issue with players using it. I never have. Certainly more and more players have started returning from further, further behind the baseline now to give themselves an advantage to return. The underarm serve is a way of saying, If you're going to step back there, then I'm going to possibly throw that in."
Murray has always been one of Kyrgios' closest allies in the sport, with the Australian's own mother citing Murray's influence in saving her son's life. Kyrgios is seeded 31st for this year's tournament and will be hoping to go one step further in his pursuit of a first Grand Slam title at this year's championships.
He added: "I don't know why people have ever found it potentially disrespectful or... I don't know. I've never understood that. It's a legitimate way of serving. I would never use an underarm serve if someone was standing on the baseline because I think it's a stupid idea because they're going to track it down and it's easy to get.
"If they stand four or five meters behind the baseline, then why would you not do that to try to bring them forward if they're not comfortable returning there? Tactically it's a smart play. No one says it's disrespectful for someone to return from six meters, whatever, five meters behind the baseline to try to get an advantage.
"So I used it not to be disrespectful to him but to say, If you're going to step further back to return the serve to give yourself more time, then I'm going to exploit that."