The red dirt on the shoes is included as Roger Federer prepares to auction off some of the kit that has taken him to a record 20 Grand Slam men's singles titles.
Among the items going under the hammer on 23 June are clothing and racquets the Swiss great used in his 2009 French Open final win over Robin Soderling - his sole Roland Garros title - and the smart white cardigan he donned for his 2012 Wimbledon final win over Andy Murray.
Roger Federer at Roland Garros in 2009. Photo: Photosport
The price tag estimates for the 20 lots being auctioned by Christie's range from £3,000 to £70,000, with the clothing and racquet he used in his victory over great rival Rafael Nadal in the 2007 Wimbledon final expected to fetch £30,000-£50,000.
If your wallet does not stretch that far, there is also an auction for 300 smaller items - such as wristbands he wore in his 1,500th professional match, in July - with proceeds from both going to Federer's charitable foundation.
"Every piece in these auctions represents a moment in my tennis career and enables me to share a part of my personal archive with my fans around the world," Federer, 39, said.
The proceeds will go to The Roger Federer Foundation to fund educational resources to children in Africa and Switzerland.
Christie's low estimate values the collection at £1m but it hopes it may reach £1.5m.
-BBC