Scunthorpe boss Brian Laws has revealed that Andy Welsh will require surgery to determine the extent of his cartilage injury.
The midfielder missed Friday's 1-0 victory over Southend after he sustained the injury in training a day earlier.
Laws is aware that the 29-year-old faces of lengthy spell on the sidelines but is hopeful he will make a rapid recovery.
He told the club's official website: "Until he goes under the knife we're not really sure exactly what it's going to be.
"Hopefully it will a Matty Godden-esque job - a clean up, tidy - we will wait and see.
"But we know he's going to be out for some considerable amount of time, but the length of that we don't know yet until we get the final result on that."