The dual-code England international has been given a Grade A one-match penalty notice for punching during Friday's costly 20-16 loss at home to bottom-placed London Broncos.
Tomkins, 32, will appeal the ban when he appears before a disciplinary panel on Tuesday night.
However, if he loses that the influential player will sit out the club's final regular round at Salford on Friday when Rovers need to win to make sure they don't have to rely on other results to survive.
Tony Smith's side are one of four clubs all locked on 20 points - London Broncos, Huddersfield Giants and Wakefield Trinity are the others - ahead of the tense last night of action.
Tomkins was penalised for punching in the second half against Broncos having apparently retaliated to contact to his face on the ground from prop Rob Butler.
Wigan Warriors second-row Liam Farrell is set to miss their game against Castleford Tigers on Thursday having received a one match penalty notice for a Grade B dangerous throw.
In the Championship, Halifax's Brandon Moore could face up to a five game ban after being referred to a tribunal on a Grade D charge of questioning the integrity of a match official.
Featherstone Rovers' Jack Ormondroyd has been hit with a two match penalty notice for Grade C Foul and Abusive Language to a match official so he is set to miss Sunday's play-offs game at Leigh Centurions.