Forest beat the R's 1-0 on Saturday afternoon as the Loftus Road outfit's poor recent form continued.
But Marsh has expressed an intriguing view on Twitter following QPR's defeat to Nottingham Forest:
Getting knocked out of the FA Cup could be the best thing that happens to QPR this season......— Rodney Marsh (@RodneyMarsh10) January 9, 2016
Forest are only a point above QPR in the Championship but will no doubt be boosted by their FA Cup win at the City Ground.
Dougie Freedman will hope the Nottingham Forest squad can take some momentum into the league from it.
As for the R's, however, Jimmy Floyd Hasselbaink has endured a very slow start indeed to his career in west London.
What can QPR fans realistically expect from their season now? Is there any chance of a late play-off bid or even a top-half finish? Should R's supporters get used to being in the bottom half - or could they even slip into a relegation battle?
In that sense, Marsh could be right about their cup exit at least doing them a little bit of good...