Jamie, Rosset is from Switzerland, he's the captain of the Swiss DC team (but sometimes also play with the team).
And he's a very good friend of Marat, which explains why they're training together sometimes.
The comment about oldness... i'm no too sure but i think he said something like that about Pioline last year too. Before the final of Bercy Marat was looking for a training partner and couldn't find any (last tournament of the season, all players were on holidays, or had left to prepare for the Masters Cup... no one in Bercy except for Stepanek, and the dubs teams).
For some reason Marat wanted to train with a French player. But they had all left Paris already.
So Cedric Pioline trained with him. And i think Marat then did say something similar to what he had said about Rosset. But i might be wrong.
Luna>> Pioline is a former player too, and now a co-director of the TMS Bercy... but see, he still trains with active players when they ask politely