Smith is a Leeds academy product
Leeds Rhinos' Lee Smith has been ruled out for up to four weeks after undergoing knee surgery following a reaction to an insect bite.
The 22-year-old winger suffered the bite last Saturday and, after the swelling failed to subside, underwent surgery on Wednesday.
Coach Brian McClennan said: "It has all happened very quickly.
"He has been taking antibiotics but the bite has got infected and swelled up over the past two days."
McClennan added: "He is still in hospital and probably will be for a couple of days."
Leeds will also be without prop Ryan Bailey for the visit of Catalans Dragons on Friday after he picked up a groin strain in training.
Second rower Ali Lauitiiti is back after recovering from a hamstring injury.