Sale's Guinness Premiership title hopes have suffered a setback after they were deducted one point for fielding an unregistered player.
The Sharks had failed to re-register David Ward following the hooker's loan spell at Manchester before including him on the bench for the Premiership game against Harlequins on March 22.
Sale, currently fifth in the table and now five points behind London Irish, need a bonus point victory at home to Northampton next weekend to stand any chance of qualifying for the play-offs.
The club was also fined £5,000 by a joint Rugby Football Union and Premier Rugby disciplinary panel.
Ward's introduction in place of a prop with eight minutes remaining and Sale trailing 31-15 to Harlequins resulted in the match finishing with uncontested scrums.
Sale lost the game 38-20.
Sale chief executive James Jennings argued to the panel that an immediate points deduction would not be appropriate because "no rugby advantage was sought or gained".
He added that any points deduction should be suspended because of the impact it could have on Sale's play-off chances.
In a statement released today, Jennings said: "The club are very disappointed that an administration failure has resulted in this sanction.
"The club, having just received the full details of the decision off the RFU panel will now study this in detail in order to consider what further actions, if any, it may take in regards to this matter.
"The club and squad remain totally focused on our final game of the regular season with the objective of securing five points in order to keep our play off chances alive."
The panel was chaired by RFU disciplinary chief Judge Jeff Blackett and comprised PRL chief executive Mark McCafferty and Jonathan Dance.
While accepting the potential impact of a points deduction, the panel concluded that "professionalism on the pitch must be matched by professionalism off it".
The ruling explained that "even apparently small mistakes can have a dramatic effect on the reputation of the overall product".
Four previous cases of administrative errors were taken into account, all of which resulted in clubs being deducted at least one point.
The panel decided to commute the penalty from two points to one in order to "reflect the club's responsible attitude in their response to the RFU".
Jennings explained in his submission to the panel that the Sale board was "appalled" at the administrative error and that he had implemented new procedures to ensure a similar breach would not happen again.
Jennings also stated that he is still conducting an internal disciplinary inquiry and is yet to decide whether any action is necessary.