Along with the events of his dramatic campaign and the demons of 2008, Billy Slater had to overcome serious self-doubt to help Australia to World Cup glory on Saturday.

The fullback revealed he was uncharacteristically nervous heading into the final against New Zealand at Old Trafford, fearing that he had rushed his return from a knee injury suffered a fortnight ago.

After working around the clock for two weeks to get himself fit, Slater was one of the Kangaroos’ best players in the 34-2 win, scoring two tries and delivering an assured performance at the back.

But right up until kick-off he was worried his troublesome left knee may not be up to the task.

“It was probably the most nervous I’ve been going into a game for a long time,” Slater said.

“Just the uncertainty of how it was going to hold up.

“I trained (this week) and, to be perfectly honest, I didn’t completely convince myself.

“I didn’t feel great but I got out there today and it was probably the best it’s felt in the last two weeks.”

Slater’s tournament was expected to be over when he suffered a recurrence of a knee injury in Australia’s quarter-final win over the US.

His relief at being able to be part of the side that avenged the 2008 final loss to the Kiwis was clear to see when he celebrated scoring Australia’s opening try.

“I’m just happy I could get out there and do that stuff again,” said Slater, who paid tribute to the efforts of the Kangaroos medical staff.

“I couldn’t walk a week ago and even a couple of days ago I was weighing up whether I would put my hand up to play or not.

“To get out there and perform the way we we did and be a part of the side we have is very special to me.”

Slater’s performance came on the back of a tumultuous campaign in which he was involved in a nightclub fight in Manchester a week out from the quarter-finals.

It also allowed for an element of personal redemption after his infamous horror pass helped the Kiwis to victory in Brisbane five years ago, though he played down those memories as a motivating factor.

“In my career, I’ve always looked forward,” he said.

Slater’s return forced Greg Inglis back to the centres and meant fellow Queenslander Brent Tate dropped out of the side.

Slater said he felt for the veteran centre and the other squad players who missed the final.

“But everyone’s played a part in this World Cup and everyone deserves to celebrate it,” Slater said.