Harlequins full-back Mike Brown will miss their Premiership opener against Bristol on Saturday due to a mystery illness.
Brown has been suffering from an unknown infection these past few weeks which has now ruled him out of the first game of the season.
Harlequins Director of Rugby John Kingston said the cause of the infection was still unclear.
"Mike Brown has had an infection and while he is now recovered from that there were a couple of weeks when he had a tough time with it," Kingston told the Daily Mail.
"We don’t yet know quite what the infection related to but Saturday has come too early for him so Mike will not be involved in the game at the weekend."
Brown did not take part fully in training on Wednesday but is expected to be back in contention for next Friday’s trip to Sale. Quins play Premiership newcomers Bristol in the second game of the Double Header on Saturday, with Saracens facing Worcester beforehand.