ANDREW Coombs hopes that three weeks of homework pays off when Wales lock horns with Tonga on Friday, writes Chris Kirwan.

The Newport Gwent Dragons captain has been a frustrated spectator at the Millennium Stadium clashes with South Africa and Argentina.

But the 29-year-old is poised to add to his six caps when the Pacific Islanders head to Cardiff this weekend.

Coombs burst onto the international scene as a lock in last season's Six Nations but has gone back in time at Wales' Vale of Glamorgan training base.

He earned a regional deal after impressing in Newport's back row and only moved forward to the Dragons' second row to cover injuries.

With Wales operating with a slimmed down squad, Coombs would be more than willing to turn out with 6 on his back for the first time since taking on the Scarlets in November 2011.

"I've been covering all positions since coming into camp and there has been a lot of homework," he said. "Wherever I go I'll be happy.

"It's been a long three weeks and it has been pretty difficult to sit there and watch the lads go out and play.

"But it's something that I have had to do and the boys have played pretty well. I always knew that it would be tough competition against Ian Evans, Alun Wyn Jones, Bradley Davies and Luke Charteris.

"I've been patient and hopefully I'll get my chance against Tonga and show what I can do. It's a big chance for everyone to put their hand up and stake a claim for the Australia game."

Coombs is set to be in the boilerhouse for what is sure to be a brutal game against a Tonga side that had scrum-half Taniela Moa sin-binned for an elbow and Sona Taumalolo red-carded for a punch-up against France last weekend.

"They are going to be very physical and it's important that we keep our discipline," he said. "Last weekend a Tongan (Taumalolo) threw a punch and the French reacted (with Yoann Maestri also dismissed), it's important we keep our cool.

"If that's the sort of game they want to play then we have to let them and leave the referee to deal with it.

"Discipline is always key at international level and we have to stick to playing our game, we can't change for Tonga.

"They are going to be looking to come at us and hit us hard, so you look to use your footwork, evade them, carry low and keep hold of the ball."

To that end defence coach Shaun Edwards has called on referee Mike Fraser of New Zealand to keep Tonga in check.

He continued: "They do go over the top sometimes, there is no doubt about it, and last weekend was a reminder about that.

"We don't mind them tackling hard, as we try to, but they need to be policed."