Japan rugby coach John Kirwan says a successful bid for the 2018 football World Cup could have a negative impact on rugby's premier competition, which is to be held in Japan the following year.
The former All Black says unless the two sports work closely together, the proximity of the events could make it harder for Japan to secure spending on Asia's first rugby World Cup.
But he conceeds hosting the rugby and football world cup's just one year apart could have it's advantages, with the potential to spread infrastructure costs over two sports.
