The NRL’s Integrity Unit is investigating “suspicious” betting activity following a plunge on Canterbury to defeat the Penrith Panthers this Thursday night.

At the start of the week, it emerged the four-time reigning premiers were planning to rest a host of star players, including co-captain Nathan Cleary.

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But before those reports surface, there was a huge betting plunge on the Bulldogs, which sparked the investigation. The Bulldogs, who opened as outsiders at $2.30, shortened to $1.60 favourites.

And on Tuesday, it was indeed confirmed that the Panthers had rested players en masse.

After successive golden-point defeats to Melbourne and Canberra left the Panthers needing a miracle to claim a top-four finish, coach Ivan Cleary has chosen to make 16 changes to the side which fell to the Raiders in Mudgee.

With players including Isaah Yeo, Nathan Cleary, Moses Leota and Brian To’o rested, coach Cleary has sat out a whopping 1,943 games of NRL experience for Thursday’s game at Accor Stadium.

Brad Schneider, who was named on the bench but did not take the field against Canberra, is the sole survivor and will play halfback in a team which includes four NRL debutants.

Austin Dias and Riley Price, the son of Bulldogs great Steve Price, will make their Panthers debuts in a side to be captained by lock Matt Eisenhuth.

The probe is separate to the ongoing Brandon Smith scandal that has rocked the NRL world.

Following the announcement of the teams, the Bulldogs were a $1.10 favourite to win, while the Panthers were rank outsiders at $8.

Ahead of the teams announcement, Cleary confirmed that he would not be playing.

“I just had a chat to the performance staff and sort of thought it’d be the best thing for me,” he said.

The Panthers are seventh on the ladder after back-to-back losses to the Storm and the Bulldogs.

Their top-eight spot is locked in but they need an unlikely series of results to go their way to fall into the top four.

Since the NRL era began in 1998, no side has won the premiership from outside the top four.

There is clearly some logic to Cleary’s thinking as he looks to defend the Panthers’ four-straight premierships.

By resting his key men on Thursday, Penrith will at least have a freshen-up ahead of next week’s final regular season game against St George Illawarra.

They should then be recharged and ready to defend their crown in the finals, where they could to face four weeks of knockout games.

Elsewhere, Melbourne have chosen to sit out Xavier Coates, Josh King and Eli Katoa as Harry Grant is sidelined with suspension for Friday’s clash with the Sydney Roosters.

Nelson Asofa-Solomona comes onto the interchange as winger Will Warbrick is named on an extended bench after a prolonged absence with concussion.

The Roosters have named Sandon Smith in place of Sam Walker (concussion).

St George Illawarra welcome back Jack de Belin, Hame Sele and Jaydn Su’A to face an unchanged Manly side on Saturday as the Sea Eagles make a late push for the finals.

Adam Doueihi’s facial injury means Latu Fainu has been named to start in the halves for Wests Tigers away to Canberra on Saturday.

Adam Reynolds is listed on Brisbane’s extended bench for their game against North Queensland later that day.

Cronulla, meanwhile, have named centre KL Iro to return from a pectoral injury against Newcastle on Sunday.

Penrith team: 1. Daine Laurie, 2. Jesse McLean, 3. John Fonua*, 4. David Fale*, 5. Paul Alamoti, 6. Jack Cole, 7. Brad Schneider, 8. Luron Patea, 9. Luke Sommerton, 10. Austin Dias+, 11. Zac Lipowicz*, 12. Mavrik Geyer, 13. Matt Eisenhuth (capt). Interchange: 14. Soni Luke, 15. Preston Riki, 16. Riley Price+, 17. Billy Phillips*.

* Denotes NRL debut

+ Denotes Panthers debut

- With AAP