Wimbledon champion Roger Federer has said that the grass at the Olympic tennis event is a "touch slippery".
The Swiss great, who has never won an Olympic singles medal, advanced to the second round of the men's singles with a hard-fought, three-set win over Colombia's Alejandro Falla yesterday.
Speaking of the surface at the All England Club, Federer said: "It's maybe a touch slippery.
"But that was the case, too, in the early rounds at Wimbledon, you know, weeks ago.
"So I think it's just getting used to understanding it's actually harder to move again on the new grass than no grass like at the end of the tournament."
Federer, who next faces Frenchman Julien Benneteau at SW19, has won an Olympic gold in the doubles, triumphing with compatriot Stanislas Wawrinka four years ago in Beijing.
