Doncaster re-signed their ex-striker on loan from Southampton in January and three goals in six games since then have provided a huge boost to Rovers' relegation fight.
Returning from suspension after a red card at Brighton, 28-year-old Sharp has netted in successive winning home games including a crucial stoppage time goal against Watford on Tuesday night.
Manager Paul Dickov told the Doncaster Free Press after the game: "If he gets chances, nine out of ten times he will score.
"He just keeps getting in the right position at the right time."
Sharp netted 10 goals in 39 appearances (9 as a substitute) for Forest last season.