This looks like a normal picture taken inside a grey tent. To make desat work you need to have something with lots of contrast and missing colors in the background people can identify with that are missing.
Wow, great capture! Pity that the selective desat is a bit messy around the arms and hands, I know how difficult and time-consuming that can be to get it right. I would have cropped a bit more from the bottom and the right to have the guys at thirds of the image. An alternative would have been to include more at the bottom to give a sense of space and height. 7