Two-brand tennis

Much has been made in recent weeks of the fact that men's tennis is effectively a two-brand commercial race: Nadal and Federer. Indeed, in Nadal's recent absence, it could well be said that men's tennis has been a one-brand sport. An interesting initial question: how long does an athlete have to be away from a sport (through injury or otherwise) before the value of their brand begins to diminish? Does it happen straight away, or does it happen over time? And what kind of rate of decline might one witness? There does however appear to be a couple of challengers on the horizon: Murray and Roddick. The commercial potential of Murray has previously been examined on this blog, although it is worthwhile asking: how will 19 Entertainment manage and generate value from the Murray brand? Those in tennis have suggested that Murray is a charming, friendly guy, which is it odds with many people's public perception of him - in what ways might an agent, manager or other intermediary be able to reconcile these two aspects of the Murray persona/brand? And what of Roddick? Unfulfilled potential - in playing and commercial terms. Is it too late for Roddick to make the big money that Federer and Nadal have, and Murray is threatening to do? Will another good showing at the US Open, after Wimbledon, be sufficient to re-establish his brand and catapult him forward into Nadal/Federer territory? Or, commercially at least, has his time passed? Perhaps his current portfolio of sponsors is evidence that he lacks the appeal of some of his rivals? Moreover, is Roddick the opposite of Murray - amiable on-court but disliked off it - which may the source of problems he and his representatives have had in building the A-Rod brand? Perhaps the relative failure of his brand is simply due no more than to his weak playing record over the years?