Israel Folau has rated Sonny Bill Williams one of the best players he’s seen in both rugby league and rugby union as they prepare to clash for the first time in seven years.

Former league internationals Folau and Williams are scheduled to play at least some part of Friday night’s final Super Rugby practice match between the NSW Waratahs and Chiefs at Campbelltown Stadium in south-western Sydney.

Each will have their first hitout of the season, with All Blacks centre Williams expected to play at least half the match for the Chiefs just six days after his last sporting endeavour in Sydney, an eight-round boxing bout which he won.

The last time they played against each other was in August 2007 in an NRL game when Folau scored three tries for Melbourne in a 38-6 flogging of Williams’ Bulldogs at ANZ Stadium.

While it’s not a certainty they will be on the field at the same time on Friday, it’s more than likely and Wallabies fullback Folau is looking forward to the prospect.

“It’s always good when you challenge yourself against great athletes like Sonny,” Folau said on Thursday.

“No doubt he’s one of the best players in both codes that I’ve seen, so it will be great to go up against him again.”

Entering his third year in the code, current John Eales Medallist Folau was adamant he still had scope for improvement.

“There’s definitely things that I can work on, both defensively and in attack as well,” Folau said.

He wasn’t giving anything away about whether he would stay in rugby after his contract expires at the end of this World Cup season.

“I’ve got a lot of options,” Folau said.

However, after playing league, union and AFL, the gifted multi-sport athlete ruled out trying his hand at boxing or the NFL.