why Nadal ? if he lost early in Rome (3rd consecutive week) he could play here.
I don't think Rafa will lose early in Rome but I'm pretty convinced he'll play in Hamburg no matter what. He has a lot of points to defend and he has never won the tournament so far - something he'd love to achieve. He might complain about the tight schedule, but that doesn't mean he'll skip a major event.
WC for Gremlmeyer looks like a pretty sure deal now.