NEWPORT Gwent Dragons star Toby Faletau may be Wales’ first choice number eight but he needs to keep on his toes to beat off the challenge of Andries Pretorius.

Much is expected from the Cardiff Blues man with Wales forwards coach Robin McBryde hoping he will fulfill his "potential" during the Six Nations.

The uncapped Pretorius was called into the national squad for the first time this week.

It means the Grand Slam champions are in the somewhat unusual position of having two players born outside Wales vying for the number eight jersey.

Faletau, 22, was born in Tofua, Tonga while Pretor-ius, 27, comes from Nelspruit in South Africa’s Eastern Transvaal.

A protégé of former Newport coach Allan Lewis at Gloucester’s prestigious Hartpury College, Pretorius qualifies for Wales after serving a three-year residency requirement. And while McBryde admits Faletau, who has won 21 caps for Wales since making his debut in 2011, is in the driving seat, he hinted the Blues captain will get his chance.

"Toby’s at the top of his game at the moment but he wasn’t at the start of the season," he said.

"You are going to get that with young players, that their form is going to be up and down, but he is playing well now."

McBryde compared Pretor-ius with Dragons lock Andrew Coombs, 28, who was called into Wales’ 35-man squad with him this week, in terms of attitude and age.

"He is similar to Andrew in age and is such a professional and we know what he can do on the field," he added.

"I don’t think Pretorius has fulfilled his potential as a player yet and there is more to come.

"And we are hoping we can see that during the Six Nations. Pretorius can offer us something a bit different.

"We are also trying to create a competitive environment in training so that when the players go out on to the field on the day of the game they are fully prepared and ready to go."