When the England head coach Clive Woodward rang Matt Stevens to invite him to join the squad for Saturday's friendly against the New Zealand Barbarians at Twickenham, he received an unusual response.

"I said I would get back to him," revealed the 21-year-old Bath prop, who has made only two starts for the club since joining them halfway through last season.

The reason for the indecision was not that he feared his inexperience would leave him exposed but the fact that he was born and brought up in South Africa and had played for them at Under-18, Under-19 and Under-21 levels.

Stevens qualifies for England through his father Russell, whose parents were both English-born. He played for England in this year's Under-21 World Cup but, realising that accepting Woodward's invitation would mean turning his back on South Africa permanently, he made a couple of telephone calls.

"I rang my father and he told me to go for it," said Stevens, who was born in Durban. "I then called my Bath team-mate Mike Catt, a South African who threw in his lot with England in the 1990s. His advice was the same and they both confirmed what I was thinking. It was a difficult decision initially because my family live in South Africa and saying yes meant I would have to live for at least the next 10 years in England.

"I am a South African but I am now totally committed to England. Getting the call to play on Saturday was a big surprise because I have only made a couple of starts for Bath and there are so many top-class props here, including David Flatman at Bath who is the best scrummager I've come across."

Stevens's last appearance for South Africa Under-21s was against England and he was asked whom he had supported during the World Cup meeting between the sides in Perth two months ago. He bought some time initially by saying that he had not seen the game, then gave a diplomatic answer.

"The Springboks played very well in the first half but England fully deserved their victory," he said. "I thought from the start that England would win the World Cup and to be playing on Saturday is an awesome prospect for me. I am determined to make the most of my opportunity."

Stevens joined Bath after enrolling at the city's university to study politics and economics. "I used to follow them from South Africa when I was a boy," he said. "They had players like Catty, Jeremy Guscott, whom I remember dropping the series-winning goal for the Lions in South Africa in 1997, Nigel Redman and Victor Ubogu.

"I supported the Natal Sharks but Bath were my other team and playing for them fulfilled a boyhood dream. The club is everything I expected it to be and it is a thrill to play before packed houses at the Recreation Ground."

Stevens is playing at tight-head prop following the withdrawal of Gloucester's Phil Vickery, who would have captained the side, and the injury suffered by the World Cup squad member Julian White. With the 35-year-old Jason Leonard nearing the end of his international career, Stevens has leapfrogged Northamp ton's Robbie Morris, who played in last season's Six Nations Championship.

Part of the reason for Leonard's long career is his ability to pack down on both sides of the scrum, an attribute Stevens shares, and he has also played at hooker.

"Matt has come on well for Bath," said the England forwards coach Andy Robinson.

"He showed his potential last season and Bath have used him wisely, giving him 25 or 30 minutes at the end of matches. Packing down on Saturday with two World Cup winners in Trevor Woodman and Steve Thompson, backed by Danny Grewcock and Simon Shaw in the second row, will help him and we want to see how Matt performs on the big stage."

Stevens scored a hat-trick of tries against L'Aquila in the Parker Pen Challenge Cup this month, having made his debut in the same competition against Saracens last season. He has made 18 appearances for Bath, 16 as a substitute, and his coach John Connolly is expecting big things of him.

"Matt is one of the best young prop prospects I have ever seen," said Connolly. "I would rather he was with us at the Rec on Saturday but that is being selfish and I expect him to grab his chance with both hands and really shine."

Stevens, a member of England's national academy, acknowledged his debt to Bath. "Mike Foley [the former Australia hooker and Connolly's assistant] has helped me enormously. I have never played before a 75,000 crowd, though I went to Twickenham last year to watch England against Italy after Mike Tindall got me tickets. I hope I get to go back there a few more times."