I now realize that my question was incorrect. The monitor profile is used to make certain that the colors you are creating on your screen are as close to perfect as possible. When your file is sent to someone who has a profiled monitor, the colors they have on their monitor will be a match to yours. Then, when they send these colors to their profiled printer, they should match both monitors. Sorry for forgetting colorsync principles.
As for proofing, if you have the printer profile for the substrate on which your image will be printed, then you can soft proof it on your monitor and also see if any of the colors are out of gamut.
I have recently experienced a printing problem where the soft proof is perfect but when it gets printed the saturation and the blues are substantially off. I just cannot understand why this is happening.