Two-time grand slam champion Stan Wawrinka admitted he struggled to recover from illness after failing to make the Australian Open quarter-finals on Monday.
Wawrinka's campaign in Melbourne was ended by fellow seed Milos Raonic, who surrendered a two-sets-to-love lead before triumphing 6-4 6-3 5-7 4-6 6-3.
The Swiss fourth seed, champion at Melbourne Park two years ago, had a cold heading into the season's first grand slam and while Wawrinka played it down during the early rounds, he was unable to shake it off in the last 16 as he lost to Raonic for the first time in his career.
Speaking to reporters post-match, Wawrinka said: "I've been sick 10 days now. [But I was] still trying to get into the second week.
"I couldn't really be at my top. When you play a top guy like Milos, it's difficult. You need to be 100 per cent to have a chance to beat him.
"It's tough to recover, to rest, and in the same time play grand slam. Today he pushed from the beginning. He was there. That's it. He was better."
Wawrinka, who failed to reach the quarter-finals of a grand slam for the first time since bowing out in the opening round at the 2014 French Open, added: "I think Milos started really well. He was pushing, playing well.
"I wasn't really feeling great there, not playing my best, wasn't moving to do something else. I'm surprised to still have went to five sets.
"For me, I tried to fight like always, tried to find a solution. I think he went a little bit down with his speed, with his movement. I took the opportunity to push him to the fifth set.
"But I'm disappointed. I know I tried what I could today."