Curbishley's side travel to Old Trafford tomorrow for a match that could have a decisive influence on the outcome of this season's championship race.
Grant will today take Curbishley to task for promising to "raise a glass" to his old friend Sir Alex Ferguson if he sees off the Blues to claim a 10th Barclays Premier League title, says the Daily Mail.
He will draw attention to a newspaper column in which Curbishley said: "It has not been a fluke that his side have been so attractive to watch and produced some thrilling football to match their results.
"It is the reason they stand on the brink of winning the Championship for the 17th time, and the general feeling among most managers is that they would like to see them crowned again.'
In the column published nine days ago, Curbishley added: "It would be a great injustice if Manchester United were to lose the Premier League title. I would raise a glass if United win the title. It would be, of course, a toast to Alex Ferguson, the best there is and may ever be."