The 25-year-old Tigers striker was flattened by an awful challenge from Guthrie during stoppage time at the end of Saturday's Premier League encounter at St James' Park.

Fagan immediately leapt to his feet after the horror tackle, which earned the Newcastle man a straight red card from referee Andre Marriner, and it was hoped no lasting damage had been done.

However, scans yesterday revealed that the former Derby man had suffered a fractured right tibia that the club believe is likely to keep him out of action for between six weeks and three months.

It is a major blow for the Tigers with Fagan having featured in all four Premier League games this term, three of which have seen him named in the starting line-up.

City manager Brown was scathing in his assessment of Guthrie's challenge on hearing the news about his striker's injury.

He said: "It cannot be tolerated, it needs to be kicked out of the game. When you see that the end product is him putting a fellow pro in a cast, it is just not right.

"That is the horrible side of the game. I don't care what is going on at Newcastle, you cannot tolerate this.

"If I go back to the incident, my players were killing time in the corner, something that every Premier League club does, no matter who you are.

"In the process of doing that, someone has decided to take the matter into his own hands and lashed out at Craig Fagan."

City sought medical opinion yesterday after the injury had swollen up over the weekend. Guthrie is likely to be hit with a three-game ban for the tackle, though it remains to be seen whether the Football Association will act further should Hull ask the incident to be looked at by the disciplinary board.

Guthrie last night issued an apology for the tackle. He said: "I was very upset to hear the news concerning Craig.

"The club have been in touch with Hull on my behalf because I want to speak to Craig in person to apologise and wish him a speedy recovery.

"It was a challenge that came purely out of frustration towards the end of the game. Anyone who knows me will accept it was totally out of character on my part."