Everton full-back Tony Hibbert will miss the start of the Premiership season after being struck down with a rare illness.
The 25-year-old has missed most of Everton's pre-season build-up, playing only two friendlies.
It has now been confirmed the problems have been caused by the cryptosporidium parasite, an illness transmitted through infected water or food.
Everton physiotherapist Mick Rathbone admitted he had not come across the bug before.
He said: 'It seems Tony has picked up a parasite, presumably when he was on his holidays. It is not that common, and the experts' advice is that he should fight it off himself.
'There is no actual treatment for it. But he should, in time, fight it off.'
Rathbone added: 'It may take days or weeks. We don't really know. We see Tony every day and he seems a lot better every day. But he hardly ate for seven to ten days and he isn't eating that much now.
'He lost more than half a stone so he is not going to return quickly. He is getting a further check this weekend and if that shows the parasite is beaten, he would still need a little bit of work before even thinking of playing a game.'