The Commonwealth Games begin in Manchester on Thursday with a record number of 5,650 competitors and officials. But will they all be returning from whence they came? Indeed, will they even all turn up in Manchester or, like the 50-odd "golfers" from Nigeria and Ghana, leg it once they set foot on English soil? It is a matter of concern for immigration authortities who are still trying to discover the whereabouts of those Africans who had entered the qualifying rounds of The Open but failed to materialise up in Scotland after departing their homelands. Could the same thing happen in the Commonwealth Games? Officials are coy on the subject, but admit they are aware of the possibility. After all, sporting defections are not unknown. It used to happen all the time before eastern European countries became more attractive to reside in than some in the west. Incoming athletes, particularly from Africa, India and Pakistan, can expect stricter than usual scrutiny. Unlike the Olympics, Commonwealth Games accreditation does not give automatic entry to the host country; a passport or visa is required so it should be easier to keep a check on "rogue" entrants. Even so, there could be dozens who will add illegal immigration to the list of 17 sports. Perhaps of even greater concern to the organisers, as well as the BBC, are defections of another sort. With athletics, always the prime attraction of the Games, shunted forward to the first week because of the European Championships, there is a danger the second half will fall flat and become something of a turn-off for the home TV audience, especially with football warming up again.