The Kenyan-born rider needs to only avoid a crash to earn his second victory at the Le Tour. Froome has faced doping allegations and abuse from spectators since he grabbed the yellow jersey in week two of the race.
"You can't prove him negative, but there is a weight of evidence to show that we are doing it the right way, we are a clean team and Chris Froome is just a fantastic champion," said the Team Sky principal on Sky Sports.
"It has been disrespectful, to come under the criticism and for people to say the things they have said about him with no foundation.
"They should go and spend their time sitting at the side of Loch Ness and waiting for a monster. It's the same thing. We have still got people camping outside with binoculars saying, 'I'm sure we are going to see the monster tomorrow', but it never appears."