Take the example of the captain of an international team who this week told a hopeful squad member that they had been omitted from the final group....by text. Possibly not the ideal method of breaking bad news while maintaining motivation and commitment.
To be effective as a leader, it isn't enough to care passionately about the team. Ask Alan Shearer (but probably not right now).
Equally, being extremely confident of success is certainly inspiring...but only if you back it up with exceptional performance (Sven Goran Ericksson, anyone?) - otherwise, you're just a false messiah.
Sport also shows us how often a great player can be an ineffective leader or manager - Bobby Charlton? Ian Botham? David Gower?
In fact, many of our most successful sporting managers were unspectacular players - take football managers: Alex Ferguson, Bill Shankly, Bobby Robson, Alf Ramsay, Jock Stein, Arsene Wenger, Matt Busby, Don Revie, Fabio Capello, Rafa Benitez - a handful of international caps between them. I recall Wenger responding to a query as to whether he had been the best player in his country by saying he hadn't even been the best in his village.... population 250!
Similarly in cricket, it's the opinion of most students of the game that Mike Brearley was a much better captain than Ian Botham or Brian Lara - yet not even in the same league as a player.
OK, this clearly isn't an absolute rule - Johann Cruyff, Franz Beckenbauer, Brian Clough and Martin O'Neill were all world class as both players and managers - but there's enough of a trend to suggest there might be some clues here.
Could it be that being less technically gifted in a field makes a leader a more effective delegator? Or more generous with praise and recognition? Or more able to accept alternative views? Or is it simply a matter of ego or temperament?
Could it be that the thing that makes a player outstanding is actually a hindrance when leading the team?