Joe Schmidt has admitted that Ireland must be wary of a "banana skin" when they take on Canada in their World Cup opener next Saturday.

Defeat to Canada would rank as one of the biggest shocks in the history of the tournament, but Schmidt believes that his side will be punished if they do not make a strong start to their campaign at Cardiff.

"I know that people probably won't see them in the same light, but I think they are an incredible banana skin for us, and you don't have to look back too far to 2007 and assumptions can undo teams very, very quickly," the Ireland coach told reporters.

"We're not assuming anything other than Canada will be right up for the game."

Ireland were knocked out of the group stage in 2007 and could only reach the quarter-finals four years ago.