He didn't even get the chance to tell his mum until after he got off the field a few hours later.

It's why Raiders coach Ricky Stuart was a bit cagey at his Tuesday morning press conference when asked who would come in for Corey Harawira-Naera to play the Canterbury Bulldogs at Canberra Stadium on Sunday.

Harawira-Naera's not allowed to play his former club - part of the deal that saw him move to Canberra mid-season.

Stuart has opted to go with an outside back on the bench with Timoko getting the nod, after playing for the Raiders in the pre-season NRL Nines in Perth in February.

The 20-year-old was tipped to make his debut earlier in the season, but a knee injury has pushed it back until round 16.

It's the only change to the 17 that beat the Gold Coast Titans 36-16 on Saturday.

Timoko will be the fifth Raider to make his NRL debut in 2020, along with under-20s teammates Kai O'Donnell, Semi Valemei and Harley Smith-Shields, and English international George Williams.

He was part of the group of young Raiders working as a teacher's aide, but he's had to put that on hold because of the restrictions due to the coronavrius pandemic.

Because Timoko's part of the Green Machine's Apollo bubble he's not allowed to do anything outside of playing NRL, training, visiting the doctor or food shopping.

"The downside of injuries is an upside of others, and that is of Harley and Semi, and now also Matty Timoko," Stuart said.

"I'm trying to use this opportunity to have these good, young, talented players get their Raiders number [369], which is their debut, and it's fully deserved because they've worked so hard without having a competition to play in.

"They've really shown some wonderful values towards the other first graders and the club itself in how hard they've worked - with all the guys that haven't been able to play, Sammy Williams and Matty Frawley - I know how hard it's been for them and it's just nice to be able to reward the odd one with a game.

"And especially their debuts... this is an opportunity [for Timoko] to start developing into a senior player.

"He's only young - he's still eligible for [under-20s]."

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Timoko's one of a number of impressive young outside backs the Raiders have coming through their system at the moment, including Valemei and Smith-Shields.

It's why Stuart's told his outside backs they need to keep performing to hold their spots.

Canberra winger Nick Cotric comes up against the club he's joining at the end of the season in try-scoring form - four tries in his past two games.

He's the Raiders' leading try scorer with 10.

While a continuation of that form will show the Bulldogs what they'll be getting next year, Stuart said it was all about the here and now.

"I just need him to play to the standard we know he can play for the Raiders. It's about what he's doing for us now," he said.

"I know that's at the forefront of his mind too. It will need to be because it's one area we have got depth in is outside backs.

"I've made it very known to our outside backs they need to be performing because I'm very, very happy to play one of those young blokes."

Just ask Timoko.

NRL ROUND 16

Sunday: Canberra Raiders v Canterbury Bulldogs at Canberra Stadium, 6.30pm.

Raiders squad: 1. Charnze Nicoll-Klokstad, 2. Jordan Rapana, 3. Jarrod Croker (c), 4. Curtis Scott, 5. Nick Cotric, 6. Jack Wighton, 7. George Williams, 8. Josh Papalii, 9. Siliva Havili, 10. Dunamis Lui, 11. John Bateman, 12. Elliott Whitehead, 13. Hudson Young. Interchange: 14. Tom Starling, 15. Joe Tapine, 16. Ryan Sutton, 17. Matt Timoko. Reserves: 18. Sam Williams, 19. Harley Smith-Shields, 20. Kai O'Donnell, 21. Matt Frawley.

Bulldogs squad: 1. Will Hopoate, 2. Nick Meaney, 3. Marcelo Montoya, 4. Kerrod Holland, 5. Dallin Watene Zelezniak, 6. Kieran Foran, 7. Lachlan Lewis, 8. Ofahiki Ogden, 9. Jeremy Marshall-King, 10. Dylan Napa, 11. Josh Jackson, 12. Raymond Faitala-Mariner, 13. Aiden Tolman. Interchange: 14. Sione Katoa, 15. Renouf To'omaga, 16. Dean Britt, 17. Matthew Doorey. Reserves: 19. Luke Thompson, 20. Jack Cogger, 21. Reimis Smith, 22. Tim Lafai.