Blackburn chief executive John Williams said: “The operation went well but the early prognosis of him being out for the season is still the fact.

“It was a bitter-sweet day for us at Newcastle. It seems every silver lining has a big, black cloud.”

Williams has ruled out a move for Barcelona’s winger Marc Overmars and manager Graeme Souness has drawn up a list of replacements for Ferguson to target during the January transfer window.

Souness said: “We were looking to strengthen before Barry’s injury but we have a budget to work from and we felt the priority wasn’t central midfield.

“But all of a sudden, that’s what it is so any money we’ve got, that’s where we’ll spend it.

“We’ve targeted a couple of players but whether we can afford them remains to be seen.”

Ferguson’s injury may mean that the board will release more money for Souness to spend.

Williams added in the Lancashire Evening Telegraph: “We have to sit down with the manager and look at what it means financially and see how we can best suit that.

“But we are talking about something that happened less than two days ago and you can’t plan in advance for something like this.”