I think it's logic that Simon replaced Monfils. I think Gilles must have been in the team for play secnd singles since the beginning. Monfils is often injured and not play a lot recently. Simon had 1/4 at Indian Wells and 1/8e in Miami and has already play on clay this season. He must pay singles with Tsonga. For doubles, i would have try new association perhaps Mahut-Roger Vasselin who ha two titles this year, or mix one of tehm with Llodra.
For USA, ISner is the firts choice and with the injury of Fish, Harrison is a legitime choice. He improved a lot since the beginning of season and he is so bad on clay.
I don't think Ryan is that bad on clay. He did get a set off Soderling last year at the French Open. He moves and slides pretty well on that surface, and actually grew up playing on clay in Louisiana.