Star off-season Sydney Roosters recruit James Tedesco has been quarantined from his teammates as the second player to contract the mumps in as many weeks.
Tedesco has been housebound this week with the contagious viral disease that was first contracted by veteran back-rower Mitchell Aubusson a fortnight ago.
NRL.com understands the NSW Origin fullback was always considered unlikely to line up in the Roosters' first pre-season trial against Penrith Panthers this Saturday, but he will now have to prove his fitness to take the park against the Manly Warringah Sea Eagles on the Central Coast next week.
Should Tedesco be kept on ice for the second trial by Roosters medical staff, it would mean neither he or five-eighth Luke Keary (fractured jaw) will have played in a new-look spine alongside Cooper Cronk before round one.
Neither player are expected to miss the club's season opener on March 10, when Tedesco will line up against his former side Wests Tigers after taking up a multimillion-dollar, four-year Roosters deal.
The Tricolours confirmed Tedesco had been placed in isolation and stressed Aubusson had shown no ill effects since being cleared to return to training.
"James has been isolated as he receives the necessary course of treatment and will rejoin his teammates next week," a Roosters spokesperson said.
A member of the club's coaching staff who also showed symptoms of the virus has recovered and returned to work recently as well, while Tedesco, Aubusson and Keary all attended last week's pre-season trip to Queenstown.
Trent Robinson will name his squad for Saturday's hit-out against Penrith on Thursday morning, with James Maloney to line up alongside Nathan Cleary at the Panthers scrumbase for the first time.