Northampton Town's Shaun McWilliams could be out for up to a month after undergoing an appendix operation.
The 21-year-old midfielder fell ill before Saturday's 2-2 draw at Oldham.
The League Two club have confirmed that he underwent an appendix operation in hospital on Saturday evening.
"It goes without saying that we wish Shaun well," said boss Keith Curle. "The medical staff are looking after him. We look forward to having him back available again as soon as possible."
The average recovery time following an appendix operation is two to four weeks.
Northampton lie ninth in League Two, two points off a play-off place.