Mam was sent an NRL breach notice on Monday for bringing both the game and Broncos into disrepute, after his high-profile driving charges in October.
AAP has been told that part of the breach notice rules Mam out for the first third of the NRL season.
He has five business days to respond, meaning he can wait until the new year to decide if he wants to challenge the suspension.
Players can ordinarily apply to have representative matches counted towards bans, including the pre-season All-Stars fixture.
Both Latrell Mitchell and Josh Addo-Carr currently have applications in with the NRL to do precisely that, as a result of their current bans relating to off-field matters.
Mam would ordinarily be eligible to play in the All-Stars match, as one of the game's highest-profile Indigenous players.
But it is understood he will not have the ability to count the game to his ban, with the five-eighth having never previously featured in the representative fixture.
It means that if he does accept the ban, Mam will be unable to return for Brisbane's Magic Round clash with Penrith.
Instead, he will have to wait another week to come back against South Sydney in round 10 on May 9 at Accor Stadium.
Ezra Mam on his way out of the Brisbane Magistrates Court. (Russell Freeman/AAP PHOTOS)
Mam's ban looms as his most significant punishment for crossing onto the wrong side of the road and causing a head-on crash in October, while driving unlicensed on a cocktail of drugs.
The 22-year-old was subsequently fined $850 in Brisbane Magistrates Court last Monday, and had his license suspended for nine months.
Mam's legal punishment has been heavily criticised as too lenient, with Queensland's deputy premier labelling it as "a slap on the wrist".
On the field, the playmaker's looming ban increased the importance of Ben Hunt's signing at the Broncos.
Hunt will now likely partner Adam Reynolds in the halves for the opening two months of the season.
It is then possible he could revert to hooker after that, if both Reynolds and Mam are fit, sharing the dummy-half duties with Billy Walters.
Adam Reynolds during a Broncos pre-season training session in Brisbane. (Jono Searle/AAP PHOTOS)
Mam's absence does loom as a blow to Brisbane as they attempt to return to their best under Michael Maguire.
The No.6 was the Dally M five-eighth of the year in 2023, with his hat-trick in that year's grand final marking one of the greatest ever performances in a losing team.
But like the rest of the Broncos team he was unable to recapture his best on a consistent basis in 2024, as Brisbane slumped to 12th on the ladder and coach Kevin Walters was axed.
Mam has since issued a public apology over the driving charges, which have headlined an unsavoury off-season at the club.
15°C