Boxing weight lifted off Sonny Bill's shoulders

Sonny Bill Williams will return to the Crusaders lineup for tomorrow night's elimination playoff match against the Sharks. Photo / Getty Images

It might not be the best bargaining chip for a future contract with the New Zealand Rugby Union, with Sonny Bill Williams yesterday admitting he felt "weighed down" by his last boxing bout.

Williams returns to the Crusaders lineup for tomorrow night's elimination playoff match against the Sharks, two weeks after bruising his hip colliding with teammate Matt Todd in the opening exchanges of the clash against the Blues in Timaru.

The 26-year-old midfielder has endured a stuttering second half of his debut Super 15 after striking up a devastating partnership with Robbie Fruean in the first two months.

At least part of his apparent tail-off can now be put down to preparation for his fight against 43-year-old gospel singing sickness beneficiary Alipate Liava'a.

"I think mentally I feel a lot fresher than I did before the fight. That sort of weighed me down a bit," Williams said. "Now I feel really energised."

On top of his rugby training, Williams also did some serious hours in the gym working on his nascent career as a pugilist while the Crusaders were in South Africa.

His contract with the NZRU allows him to also pursue a career in the ring, but the policy has not been without its critics. The alternative of Williams walking away from the sport he has made such an instant impact in seems worse, but the timing of his bouts need closer scrutiny following his confession.

Yesterday, Williams said he would wait until the end of the season before making any decisions on his future though the NZRU has made it clear they are prepared to be flexible, as they have with Richie McCaw and Dan Carter, to keep him in the 15-man game.

Of more immediate importance, Williams said his hip was still tender, but manageable.

This will be Williams' first experience of the pointy end of a Super rugby season, but he's been through an NRL playoffs with the Bulldogs in 2004.

"Big games are where the big players stand up - and the big teams. You know we've been through a lot of adversity this year but we can't use that as an excuse and we won't."

Williams said the Crusaders had struggled to adjust to poor weather in recent weeks, but is convinced that will change against the South Africans.

"We know that the Sharks are a big physical team and that they'll come to play physical rugby for the whole 80 minutes so we've got to be prepared for that." The Sharks arrived in the country yesterday after a gruelling travel schedule that took them from Pretoria to Johannesburg to Durban, and on to Wellington via Sydney.

They will make the short hop to Nelson this morning.

Coach John Plumtree recognised, however, their journey paled in comparison to what the Crusaders have been through this season.

"[It] has been remarkable," Plumtree said.

"They are a champion side. The earthquake and how it has affected people in that area has just bonded them and made them tougher to beat.

"There are not too many sides who could have done what they have done."