Roger will not drop a set in his way to the semis, Murray might have to fight for his life from round one.....Novak will show who is #2 on clay and Rafa...........will play his best tennis of the season yet.
By losing badly in the semis to Federer?
AS for Murray, he's weak on clay, but Chela is ranked 205 for a reason: he's just been beaten in straight sets by Oscar Hernandez, over tyhe clay season he's lost to Bolelli and Rochus, his best wins have been against KUnitsyn and GIcquel, he has a negative record this year, he hasn't beaten a top-30 player without a retirement since the 2007 US Open. Murray beat him 3 times in straight sets before he started shaving and when Chela was still a top-30 regular. Murray is miles out of Chela's league. As for the other threat you named: Starace, he is ranked 105, also has a negative record for the year, retired in his last tournament, and his form, while beingh better than Chela's is still pretty poor compared to Murray: wins over Hernandez, Gulbis and Soderling on clay are nothing to write home about. The early 'scares' for Murray could only be Zverev if he plays like he did in Rome, or Montanes: they are the two best clay-courters in Murray's section befotre the quarter-finals. Murray couldn't have asked for a better draw.
Full list of players in Murray's section: Chela, Zverev, Starace, Tipsarevic, Montanes, Feliciano Lopez, Stepanek, Gaudio, Lu, Sela, Hernych and Cilic. i.e. a set of half-decent seeds who hate clay and a lot of journeymen who would say they like clay but Murray can totally outclass.