Only three weeks into the new season, Juan Martin del Potro, last season's US Open champion and the world No 5, appears to be fraying at the edges, with the Argentinian losing a fourth-round, five-set match to Croatia's Marin Cilic.
In the days leading up to this Slam, Del Potro was unable to practise because of a wrist injury, and it was tricky to keep track of all the injuries and medical complaints that he has had at Melbourne Park.
A sore foot was one problem, another was general fatigue. "My whole body is sore. I will go home and see my doctors there and have some rest and recovery before the next tournament," said the South American, who was on court for more than four and a half hours before Cilic won 5-7, 6-4, 7-5, 5-7, 6-3.
Cilic will play Andy Roddick, after the American came from two sets to one down to defeat Chile's Fernando Gonzalez 6-3, 3-6, 4-6, 7-5, 6-2. It means Cilic or Roddick will play Andy Murray or Rafael Nadal in the semi-finals.
Justine Henin, who is appearing at her first grand slam since returning to the tour earlier this month, reached the quarter-finals when she beat her fellow Belgian Yanina Wickmayer 7-6, 1-6, 6-3, and the 2004 champion will next play Russia's Nadia Petrova.
Maria Kirilenko continued her progress when Dinara Safina, the world No 2 and last season's runner-up, retired in the first set because of pain in her lower back. (©Daily Telegraph, London)