Sheepish Federer apologizes for dissing Tomic

Roger Federer apologized on Tuesday after he sparked a row with Bernard Tomic by upbraiding the Australian about his work ethic - without checking his ranking first.

Federer told Tomic he had to work harder if he wanted to reach the top 10, prompting Tomic to point out that the Swiss great was also some way away from the level of top-ranked Novak Djokovic.

But Federer admitted on Tuesday that he made the comments thinking Tomic was still ranked at about 50th in the world.