Would be an interesting matchup... worth a dedicated thread imo.
i still think nadal will take it on a best of three sets, but a best of five might give Ferrer more of an edge. I'd say 50/50 on a best of 5 set clay match. i actually think nadal would do better against him on other surfaces as he'd be able to hit through the court more and come in to close out points.
There is time from now until roland garros. i think nadal should focus on getting healthy rather than worrying about results until then.
Disclaimer: I'm NOT a coach...
Real tennis: https://www.youtube.com/watch?v=yDqnkLJ9BtM