Warrington have lodged a protest with the Rugby Football League accusing the Bulls of having 14 men on the field during Tuesday night's 22-22 draw.

The appeal is believed to relate to an incident in the sixth minute when Aaron Smith was replaced by Jamie Langley after suffering a nasty head cut as the Wolves laid siege to the Bulls line.

The Bulls medical team quickly halted the flow of blood and Smith retook the field without realising he had been replaced.

The hooker is believed to have been on the field for 30 seconds, during which time the Bulls defused a kick into their in-goal. Smith was well away from the play at the time.

Wolves head coach Paul Cullen said in a statement: "It's wise at this time to allow the RFL to conduct their own full and proper inquiry."

The statement said the club were "are awaiting an unofficial response from the RFL" over the incident.

The RFL would not comment on the matter other than to say the complaint had been passed to their disciplinary commissioner. If the commissioner rules the Bulls have transgressed he has unlimited powers to impose any punishment he deems fit, said an RFL spokesman.

In a similar incident in the Australian NRL earlier this season the Brisbane Broncos were docked two competition points for fielding 14 men in a victory over Wests Tigers. Although on that occasion the player in question, Corey Parker, ignored two warnings not to take the field and scored a vital try within seconds of doing so.

England's World Cup-winning rugby union team also fielded an extra man during their hard-fought victory over Samoa in a pool match. Winger Dan Luger took the field despite being instructed not to while centre Mike Tindall was being treated for an injury. England were fined $A25,000 for the transgression.

Bulls football manager Stuart Duffy said the club would not comment until the RFL had completed their investigation into the matter.

l Huddersfield Giants' Mick Slicker has signed a two-year contract extension that will keep him at the McAlpine Stadium until the end of the 2006 season.

The 25-year-old former Cougars prop said: "I've been here just over three years now and the progress made since I first came has been incredible."

l The Bulls U21 academy side entertain Wakefield at Odsal tonight (7.30).