Warrington's veteran second row Ben Westwood has been banned for four games after being sent off for a headbutt against Wigan on Friday.
The 37-year-old former England forward reacted after a melee towards the end of the Super League game and appeared to headbutt Wigan's Morgan Escare.
He pleaded guilty, but lost a challenge over the RFL's decision to deem it a Grade D headbutt offence - the third-highest level of sanction in Super League.
He has also been fined £500.
An RFL statement read: "The challenge to the grading was unsuccessful and the tribunal found the grading at grade D was correct and appropriate."
Westwood will miss Thursday's trip to Wakefield and subsequent matches against Hull FC, London Broncos and St Helens. He is free to return against Salford on 19 April.
Meanwhile, Wakefield's Danny Kirmond has been given a two-match ban.
Kirmond was found to have made dangerous contact with an opponent who was kicking the ball during his side's Super League clash with Hull FC.