MELBOURNE, Australia - The relationship between likely 2014 Formula 1 title contenders Lewis Hamilton and Nico Rosberg may already be strained in the Mercedes garage.Their friendship dates back to boyhood in the junior categories but it could be tested to the limit in 2014 despite the team and its Mercedes 'power units' looking likely to dominate the 2014 title battle.Hamilton was quoted by the German newspaper Bild as saying: "Rosberg often spends much more time with the engineers than I do but we come to the same findings in the end."SIGNS OF STRAINHamilton bristled at the suggestion that Rosberg had a better chance of taming the highly complex 2014 rules because of his "more technical" approach to racing. "It's a strange perception that one driver (Rosberg) is massively technical and another is not."I didn't win the championship in 2008 from sheer luck."Rosberg insisted the comments, particularly about wasting time with engineers, would not affect their relationship. "It's no big deal for me,two different approaches is a good thing."NO WEDDING INVITEHowever, even though each lives in Monaco, Hamilton has not been invited to Rosberg's forthcoming wedding. "I don't mind," Hamilton said. "I try to avoid weddings anyway."Meanwhile, some of the British news media have criticised Hamilton for making "strange", "bizarre" and "insensitive" comments about the gravely injured Michael Schumacher. Referring to the F1 legend's 11-week coma since a skiing fall the 2008champion said in Melbourne: "I feel like all things happen for a reason."I think this is an experience that will really show his character and depth even more so than any other experiences he's had."Stay with Wheels24 for the first 2014 F1 race in Australia this weekend.