Rovers' manager, Roy Hodgson, said Davies was "very ill" and would be out of football for the foreseeable future. The former Chesterfield striker missed Blackburn's Premiership defeat to Chelsea on Monday with what the club were informed was tonsilitis.
However, his condition has deteriorated, and Hodgson added: "Kevin has gone into hospital. It's a throat infection of some sort or other, but he is not well at all. We will wait to see what the medical people say."
Davies has had a difficult time since his big-money move from The Dell. After starting the season alongside Chris Sutton, he lost his place and regained it only when his rival, Kevin Gallacher, was injured.
Davies has not yet scored a goal for Blackburn, and his illness has left Rovers with a striking crisis. Gallacher is still suffering from a calf strain, while Chris Sutton may require surgery to solve an ankle injury and has pulled out of today's trip to Everton.
"These things happen in football, and the timing of all the problems could not be much worse," Hodgson admitted. "Every player is different, and it's rare when you have ready-made replacements." He is left with just Martin Dahlin as a recognised front-runner but he does have the Irish winger Damien Duff back in contention after a thigh injury.
George Graham will be given pounds 18m to transform Tottenham's fortunes if he becomes manager, according to David Pleat, Spurs' director of football, who is looking after team affairs.
"We have resisted buying mediocrity and it is a great challenge for somebody," he said. "The club needs three quality players, of course we do. If we buy two or three top players for about pounds 18m, we can become a top six club again. The new manager will have that money available."
Pleat also said that Graham's appointment, if it happens, must be done by the book or not at all. "I am part of the League Managers' Association, and we have been concerned recently about players who are so financially secure that they have threatened to withdraw their labour," he said. "Therefore it is important that we be seen, as managers, to be doing the right thing."
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