Hull striker Daniel Cousin will be out of action for at least 10 days after being told he requires minor knee surgery.
Cousin was left out of last weekend's 2-2 draw with West Brom in the Premier League in the hope that rest would cure the problem.
But it has since emerged that the injury is more serious and he will have an operation similar to one that laid off Bernard Mendy for a couple of weeks in November.
Manager Phil Brown said: "Daniel needs a minor operation. It was first assessed on Monday and Daniel was quite adamant that he didn't need one.
"But he has understood that we have top-class medical people at the club and he now needs an operation.
"We may have wasted two or three days but he is going in tomorrow.
"I don't know how long he will be out for but we have a history at this football club of getting (players with) meniscus back on the training ground after 10 days.''
Hull's other major injury concern is record signing Jimmy Bullard. The midfielder jarred his knee on his debut against West Ham on January 28 and missed the visit of West Brom.
The injury is not connected to the one which sidelined him for 15 months in September 2006 but Brown admits he is not yet sure when the 30-year-old will be fit to return.
Hull are awaiting the verdict on scan results which have been sent to Bullard's surgeon, Dr Richard Steadman, in Denver, Colorado and he looks doubtful for Saturday's trip to Chelsea.
Brown added: "The scan situation hasn't become farcical but it has been delayed.
"Because it has been delayed Jimmy's knee has settled down, the swelling has completely gone. That might be a blessing in disguise but we will see how Jimmy is today [Thursday].
"It has got nothing to do with the old injury, Jimmy has played 40 or 50 games since then. It is unfortunately the same knee but it is a totally different injury.''
Brown is hopeful defender Anthony Gardner might be able to return in next week's FA Cup fifth-round tie at Sheffield United.
Gardner has not played since September and made just three appearances since joining Hull from Tottenham for £2.5m last summer due to thigh problems.
Brown said: "He is not available this weekend. We go warm-weather training after this game in preparation for the Sheffield United game and hopefully Anthony Gardner will play some part in that.''
Brown claims to have been taken aback by the strength of chairman Paul Duffen's public show of support this week.
Duffen branded "disgraceful'' the "vocal minority'' of supporters who have criticised Brown after a poor run of form and the failure to sign a player on transfer deadline day.
Brown appreciates the backing of his chairman but says the whole episode has left him bemused.
"I was surprised and quite shocked from what I saw this morning, why I was being defended so much,'' Brown said. "Maybe I haven't got my ear to the ground as much as I thought I had.
"Criticism is part and parcel of the game and it goes hand in hand with managing any football team, regardless of whether you are Premier League or lower division.
"It maybe makes more of an issue of it but I don't know, because I have not heard the comments that he is for some reason backing me for.''
Brown insists he is prepared to handle any criticism when it comes.
He added: "I like to fight my own fights, put it that way.''
Brown brought in Jimmy Bullard, Kevin Kilbane and Manucho in January but had hoped to bring in two more faces before Monday's deadline.
The club did speak to Roma defender Christian Panucci but attempts to bring the veteran and other targets to the KC Stadium all failed.
Brown admits it was a frustrating experience and has hit out at the whole concept of a mid-season transfer window.
He said: "We were hoping for one or two but the reason is not where Hull City is in the Premier League, the stature of the football club or the stature of the players - it is the transfer window that was standing in our way.
"It was just ridiculous what happened on Sunday and Monday but as far as we were concerned we weren't going to be held to ransom by players, agents, money, whatever.
"Unfortunately if one or two are disappointed supporters-wise, that is the way it is.
"For me, having a transfer window is a waste of time. It wastes energy, it saps you.
"As far as I am concerned they should open the window in summer and close it in summer, then get on with whatever squad you have got.
"The transfer window is a money-making venture for non-footballing people.''