South Africa coach Mickey Arthur says he is "scared" about the potential growth of Twenty20 cricket at the international level.
Arthur was speaking at the MCG on the eve of the first of two Twenty20 matches between the Proteas and Australia, the abbreviated form of the game now having become a regular component of many tour schedules.
Its popularity at both domestic and international level led to the staging of the first Twenty20 world championship in South Africa in 2007 with a second tournament to held in England in June.
Arthur says the International Cricket Council needs to be cautious about increasing the number of international Twenty20 matches, as any such move may be "overkill".
"I really do just get scared of it becoming too big a concept internationally," he said.
"Two Twenty20s a tour and a World Cup every two years is probably spot on."
Arthur, who admits to being a cricketing purist, says any increase in Twenty20 scheduling at the international level may harm spectator interest in domestic competitions such as the Indian Premier League, which he believes is "unbelievably good" for the game.