Wales have the potential to cause a shock at the World Cup as an underrated team, according to former New Zealand scrum-half Justin Marshall.

With just two teams progressing from Pool A, Warren Gatland's side have a fight on their hands to upset either England or Wales if they are to reach the quarter-finals from a group which also includes Uruguay and Fiji.

However, Marshall, who played in Wales for two years with Ospreys, believes that they can make full use of being underdogs.

"They've got an opportunity to be that silent assassin team because they've slightly been written off," he told BBC Sport.

"What a great opportunity for Warren Gatland and [captain] Sam Warburton to get together and go 'they've kind of written us off, let's sneak into Twickenham and ambush England and let's put the sword to Australia," Marshall told Sport Wales.

"I'm very much watching with great interest as to Wales' performances in the pool stages as they could upset and they could qualify."

Wales meet Uruguay in Cardiff on Sunday.