INDIAN WELLS (AFP) - Roger Federer, something of a tennis purist, hopes the innovation of on-court coaching adopted on the WTA Tour does not come to men's tennis.
"If it does happen, it's hopefully after I'm done playing," the 17-time Grand Slam champion said on Thursday after booking his semi-final berth at Indian Wells, where the ATP Masters tournament is combined with a WTA event.
"I really don't think it's necessary. I don't think it's fair maybe, because not everybody can afford a coach...it's just not right."
The WTA has allowed limited on-court coaching since 2009, with players able to call for their coaches at one changeover per set, and between sets.
It is not allowed in Grand Slam tournaments, and Federer conjured a dire picture of what could happen if the ATP Tour adopted a similar rule.
"We'll see girlfriends walking out, we'll see parents walking out. It's not going to be pretty," said the Swiss great, who was also wary of the Hawkeye electronic line call review system when it was introduced.
Earlier, he kept his bid for a fifth Indian Wells ATP Masters title on track with a 7-5, 6-1 victory over Kevin Anderson.
The 32-year-old needed just 69 minutes to book his berth in the final four, where he will face Ukrainian Alexandr Dolgopolov.
The subject of coaching came up after Thursday's WTA quarter-final clash between Flavia Pennetta and Sloane Stephens, in which Pennetta, up a set and 5-4, called her coach out for a chat on the changeover and promptly dropped three games and the set.
"Clearly when the coach comes on and they go on a losing streak, that wasn't helpful," Federer said with a smile.
Mainly, however, he said he believed that the individual nature of the sport was part of its attraction.
"It's cool to figure it out yourself," he said. "You can look over to your coach for comfort and support, but other than that, I think tennis should be one of those unique sports where you don't get coaching."
The 20th-seeded Italian Pennetta eventually prevailed over the 17th-seeded American Stephens 6-4, 5-7, 6-4, and will meet top-seeded Chinese Li Na in the semi-finals.