Joseph Parker believes All Blacks star Sonny Bill Williams will return to boxing

Williams beat Frans Botha in 2013 to claim the WBA international heavyweight title. Chris Hyde/Getty Images

Joseph Parker believes All Blacks star Sonny Bill Williams will return to boxing one day, and he also stated his own upcoming fight against Anthony Joshua will put New Zealand "in the history books".

Williams has boxed professionally in the past and even won the New Zealand heavyweight title in 2012. He currently holds an undefeated 7-0 record but hasn't fought since his victory over Chauncy Welliver in Jan. 2015.

There have been recent discussions over Williams' future in rugby union, and Parker believes the 2015 Rugby World Cup-winner, who he has previously sparred with, could even return to professional boxing one day.

"Sonny is great athlete, you know," Parker told ESPN. "We have been texting a bit and keeping in touch.

"He's focused on his rugby at the moment and his family, but overall he's a great athlete. I think he'd love to get back into the ring but he's focusing on a few things for now.

"One day he will come back and fight but at the moment he's just concentrating on his family and rugby, but I think his passion for boxing is still there."

WBO heavyweight champion Parker (24-0, 18 KOs) challenges Joshua for his IBF and WBA straps on March 31 at Cardiff's Principality Stadium.

In a fight which is expected to fill out the 74,500-seater arena, the New Zealander believes the bout will attract global appeal and help to give his nation more worldwide recognition.

While Parker acknowledged rugby will continue to be New Zealand's national sport, he believes interest in boxing is growing in the country and revealed that some of the All Blacks may attend his fight despite the mammoth 18,891 km distance between capital city Wellington and Wales' Cardiff.

"I think some of the players might be free and might come over," Parker added. "I'm good friends with Jerome Kaino, Israel Dagg, Sonny Bill. I think if some of them do get time off they'll definitely come over and support.

"This is a fight where I think the whole of New Zealand are going to back us, and it can be a fight where we do well. It's going to put New Zealand boxing on the map and it's going to put us in the history books.

"As our team, we love a challenge. We love the challenge over fighting overseas. We love the challenge of fighting infront of 80,000 people so it's going to be an experience that everyone's going to come along for the ride and enjoy."

New Zealand's next rugby fixture is at home to France on June 9.