Newcastle forward Steve Simpson is set to put family ahead of possible World Cup glory by officially withdrawing from Australia's squad for the end-of-year tournament.

The Test backrower, capped seven times, was named last week in the Kangaroos' 46-man preliminary squad.

But with his wife due to give birth in early October he was poised to ask for an exemption for the showpiece international event of rugby league's centenary season, which stars later that month.

"I think I might have to pull out," Simpson said.

"My wife's due to have a baby in early October so it's going to be a bit of a tough time for her and for us, having a new baby.

"We also have an 18-month-old boy, so we'll wait and see what happens, but it's going to be pretty unlikely.

"I haven't spoken to anyone (at the Australian Rugby League).

"I just found out I was in the squad the other day and I'll have to take the appropriate sort of action and speak to the right people.

"I'd love to play, and I think if my wife wasn't pregnant I'd love to jump at the opportunity but it's one of those things, you want to be there for your family as well, it can be a pretty tough time, and an exciting time also, so it's something I don't want to miss out on."

Simpson's decision may also be a blow to Ireland's World Cup campaign, with the second rower eligible to play for the Irish if he was not selected in Australia's final squad.

The 28-year-old has endued one of the most frustrating seasons of his NRL career with a run of injuries restricting him to just eight of 21 games for the Knights.

He was back to his brutal best on Monday night, though, playing a leading role in the Knights' 32-12 win over Parramatta in his first game back after a month off with a hip problem.

Coach Brian Smith, in particular, was in awe of his star forward's ability to be so dominant in his first comeback match.

"The way he carried the ball and smashed blokes, he was awesome," Smith said.

"I said to the boys after the game, I thought Simmo's performance, if you contrast other players ... where they've come back after injury, it was a credit to Simmo just how dominant he was."

Simpson, himself, was just happy to be back out on the pitch to help Newcastle claim a spot in the top eight with five rounds to go.

"When you come back from a couple of little injuries you always have a few butterflies there, so it's good to get out and play some minutes and get out of it pretty well," Simpson said.

Brought to you by AAP © 2024 AAP