'Old man' Sonny Bill Williams grilled by kids ahead of Super League debut

Sonny Bill Williams is preparing for his Super League debut, but he had to face another big challenge this week in the build-up - questions from starstruck kids.

Williams will run out for the Toronto Wolfpack for the first time on Monday morning NZT after signing a two-year, $10 million deal with the club last year.

But before he could take on the Castleford Tigers in Leeds, Williams sat down with some aspiring young rugby league players to talk about his life and career.

The in-awe kids asked Williams a wide range of questions which the former All Black appeared happy to talk about.

One youngster asked him what it was like to play in a World Cup final, to which the 34-year-old gave a well-rounded answer.

"I've played in three World Cup finals: one rugby league and two in rugby union. It's very tough, there's a lot of pressure, but it's really exciting," he said.

"When you work as hard as you can all your life to get to a place and a point where it's the pinnacle and it's the best thing you can do, so when you get there, the way I think of it is when I get there, why am I going to be so scared about this experience?"

Another child asked a trickier question of the code-hopper, wanting to know who was the best player he has ever played against.

In response, Williams narrowed his answer down to two rivals.

"I don't know if you guys would know a guy called Adrian Morley? He would definitely be up there. He was really tough. Not as tough as me, though," Williams joked.

"And another guy called Sam Burgess. They'd probably be the best Pommy players that I've played against."

Williams admitted there were probably others but there was a lot of memories to try and sift through.

"I've been playing this game for 20 years, so twice as long as you guys have been alive."

The final question Williams faced was what was his biggest sporting achievement to which he gave a surprising answer, considering his resume.

"Still being here, still playing professional sports at the highest level after 20 years. Longevity. Do you know what that means? That means still playing the game, being able to play rugby league for so many years. This will be my 18th year playing professional sport."

Williams wrapped up question time with a couple of photos with the children and some high fives while also admitting one last truth.

"I'm an old man now."