Written by a group claiming to represent 4000 Blackburn fans, many of them season ticket holders, the open letter was a series of individual messages from fans venting their frustrations on Kean's performance.
Their worries are understandable as the Lancashire club are bottom of the table after losing all three matches so far.
The fans claim have seen the club in worse situations before, yo-yoing in between the first and second tier English football, but they are especially frustrated by the mismanagement of Kean.
One fan, who compared the current manager to previous ones such as Paul Ince, Brian Kidd and Roy Hodgson, stated that past managers have been given the sack for better performances, and that enough patience has been granted to Kean.
He wrote: "Kean has had 6 games more than Ince, but still only won the same number of matches - enough to get Ince sacked. Neither Ince (28.6%) nor Kidd (27.3%) have a worse win % than Kean (22.2%). Both Ince and Kean have lost more than half of the games they have been in charge for (both 52%).
"In all of these examples either relegation or the sacking of the manager followed."
Another fan also wrote: "At the moment, current manager Steve Kean's win record is actually inferior to Paul Ince's. If quick action is not taken, the damage will already have been done, and it will be very difficult for Blackburn Rovers to recover."
They also slammed Kean's perceived mismanagement of the club, criticising Kean's insistence on playing misfiring striker Jason Roberts despite having strikers like Mauro Formica, Ruben Rochina and having signed David Goodwillie over the summer.
"There are odd team line-ups where under-performing players such as Jason Roberts and Michel Salgado continue to play whereas goalscorers Mauro Formica and David Goodwillie drop to the bench.
"Jason Roberts who has average a goal every 5.4 games is played as a sole striker leading the line?! Then Kean says he can't understand why the team is not scoring goals?
"He sells the best striker we got (Kalinic) and now just plays Roberts one game after another, frustrating!
"Seems to be that Roberts is first name entered on the team sheet, regardless of his lack of goals, when Rochina has proved he has goal scoring ability, why?
With only three wins to their name last season, Blackburn Rovers are in real danger of becoming relegation candidates once again despite finishing seventh in the table in 2008 under Mark Hughes.
A recurring theme in the letter was an appeal for action before the situation worsens.
They wrote: "A very real fear for the future is now setting on Rovers fans. Numbers speak louder then words. More than 1,000 season tickets down on last season?"
"The fans are united in one opinion. The opinion that Steve Kean needs to be removed as manager.
"As you can tell, we are passionate football fans. We love our club. Some fans are angry, some are depressed about the current situation and some are desperate for change.
One fan felt that rehiring Hughes, who resigned as Fulham manager in June, could bring back better days.
"Under Mr Hughes, any game was winnable. I mean for goodness sakes who would have thought we would have beaten Manchester United both home and away under him?!"
This comes after Kean's admirable performance in the transfer window, where he managed to lure Scott Dann to the club while retaining the services of Chris Samba.
In any case, one feels that Blackburn's match against Fulham on Sunday may be the biggest yet in Kean's management career.