Rafa mentioned in his presser that he will travel to Mallorca on Thursday. So, he will have a couple of days to relax with his family (he mentioned his little cousins) and then start preparing for the clay court season. That gives him about a week of practice.
I think he will have enough time to play himself into form. Monte Carlo is crucial for his confidence, though. Last year he lost the Final to Nole and that did not seem to affect the rest of his clay season. But the circumstances were different then. He had just won Indian Wells and had about a month long break to recuperate, rest, and prepare for the clay.
This year he only has a week. The loss to Nole in Miami is probably still on his mind. Also, he might be still a little cautious about his back problems and not go out and serve/play at 100%.
I have seen Rafa battle through much tougher times so I am confident he will bounce back again. Can't wait for Monte Carlo 
Yay, optimism! I was starting to become a Negative Nancy.