Thompson copped a one-match suspension on Tuesday for the grade-two dangerous contact charge he was hit with after Newcastle's 14-12 win over Melbourne.

The Knights forward made contact with Ryan Papenhuyzen as the Storm fullback was leaping to catch a kick in the 65^th minute.

Papenhuyzen was whipped into an airborne rotation before landing heavily on the turf.

Thompson had kept his eyes on the floating ball the entire time and made no attempt to tackle Papenhuyzen, but was still charged.

The New Zealand international was facing a two-match ban if the Knights contested the charge at the judiciary and lost, but with an early-guilty plea will only miss the match against the Warriors in Auckland.

Knights football director Peter Parr told the Newcastle Herald on Tuesday that multiple factors had swayed the club's decision for Thompson to cop the one-match ban, but having him available - and fresh - for the next game against St George Illawarra was a key consideration.

The Knights play in Auckland at 6.05pm local time and won't depart New Zealand until Monday.

They then host the Dragons just a few days later at 8pm (AEDT) on Friday.

"We talked a fair bit about trying to get a downgrade," Parr said.

"But they judged that the force was moderate and the risk of injury to the opposing player was moderate.

"We felt to try and get those down to low, whilst we felt there was an argument for that, we didn't think it was probably strong enough to convince us we'd get the result.

"For him to miss both of those games - missing one is bad enough - but missing two is something we weren't willing to risk, really."

Fellow Knights prop Jacob Saifiti, who will now start alongside brother Daniel against the Warriors, said Thompson was shattered to be missing out on playing in his home country.

"I think he already had some tickets lined up for his family and mates," Saifiti said, speaking at a pre-Easter visit to John Hunter Children's Hospital on Tuesday.

"He's going to be sorely missed.

"The work he does off the ball that the untrained eye wouldn't notice, that's really what Leo does best.

"We'll definitely have to pick up that slack."

In a timely boost for the Knights, Jack Hetherington is set to return from injury, while coach Adam O'Brien has promoted Brodie Jones to the bench in favour of back-rower Dylan Lucas who has been named 18^th man.

1. Kalyn Ponga (C)

2. Tom Jenkins

3. Dane Gagai

4. Bradman Best

5. Enari Tuala

6. Tyson Gamble

7. Jack Cogger

8. Jacob Saifiti

9. Phoenix Crossland

10. Daniel Saifiti

11. Tyson Frizell

12. Kai Pearce-Paul

13. Adam Elliott

Interchange

14. Jayden Brailey

15. Mat Croker

16. Jack Hetherington

17. Brodie Jones

Extended match squad

18. Dylan Lucas

19. Jed Cartwright

20. Tom Cant

21. Will Pryce

22. Jackson Hastings