Allan was ruled out for up to six weeks on Friday after sustaining a groin injury at training, opening the door for a Bulldogs junior to join recent debutants Jacob Kiraz and Kurtis Morrin in first grade.
22-year-old Declan Casey made headlines in the pre-season with a massive shot on Kalyn Ponga in a trial game, however the speedster has spent the entire season in NSW Cup plying his trade in multiple positions across the backline.
Coming through the grades at fullback, Casey has spent time in the number one, on the wing and in the centres so far this season, with Matt Dufty's recent dropping to reserve grade allowing Casey to find a home in the centres.
There is still a chance that Casey could push wider, with Kiraz and Allan swapping between centre and wing at times during games, and lining up against rep stars in Siosifa Talakai and Ronaldo Mulitalo, they will need to find their groove early.
Casey will have some decent-sized shoes to fill, with Allan one of the only Canterbury players to have a winning record this season. Injured for the early parts of the season, the former Rabbitoh has played in the last three games for Canterbury, losing a close contest to Penrith before victories over Parramatta and Wests.
One person who won't be there to hand Declan his maiden first-grade jersey is interim coach Mick Potter, who will coach this week's game from his lounge room after contracting COVID earlier this week.