That would be shortsighted, in my opinion.
He has to get rested for the important tournaments: Olympics, Canada, Cincy, USO.
He has played 2 tournaments who count as 500s: Dubai and Monte Carlo. He can play Beijing and Basel and make up for last year's underperforming, to make sure he ends the year as #1.
If he gets distracted by clay and then loses in the Olympics or Masters it will be very difficult to regain the #1.
Don't give so much importance to one match when he was low on energy. That's tennis. He'll bounce back. He may even beat Roger on grass fighting for the gold medal.
One question: why are Roger fans visiting us? Are they not happy enough with their man that they have to come her? So Nole is in Roger's head (did you notice how many times he mentioned his losses to Nole?) and we are in Roger's fans' heads... Me likey.
Unless you have been living under a rock, he has been weak in the main tournaments and he is not winning.
In the RG, he played like he didn't want to be there and the less said about wimbledon , the better.
So there is no basis to say that lower tournaments can ruin his "preparation" when he is not winning but he desperately needs optional points.