Argentina captain Lionel Messi vomited during the World Cup final, as he has done on many occasions both for Argentina and club team Barcelona. (Five Moments Where Germany Trumped Argentina for World Cup Title)
It was during the first half against Germany that Messi doubled over and vomited on the pitch. (FIFA World Cup Final Highlights)
Despite several medical tests, Argentina and Barcelona team doctors haven't been able to find the cause of Messi's problem. (Germany's triumph result of team work, says Philipp Lahm)
The striker has played it down, saying it's just something that happens to him in training, during matches and even when he's at home. (Lionel Messi squanders chance to join greats)
It doesn't appear to affect his performance, though. Messi has gone on to score in several matches after throwing up on the pitch.