Ruben Ramirez-Hidalgo is an intruiging player. A complete nobody who near the age of 30 worked himself up to be a competitive claycourter (2006-2007), beating Ferrer at RG, leading Federer 5-1 in the final set in Masters Series tournament.
His playing style is also of interest, he is the most technically pure moonballer on the tour
miles ahead of Nadal in esthetic terms, complete with a never-failing trademark grunt. A legend.
Also on clay, not Marcos favourite surface. Those double players do not attack the net all the time, but they can be good, especially returning serves.
Marcos is searching for it (changing coaches, gymnasts and academies). He has not been successful so far but he seems to be trying. I believe he sould try searching within himself. He has the tennis, but he has to find a way to take over his mind