Bennett joined the club from local amateurs Golborne Parkside

He joins fellow back-rowers Lee Gilmour and Jason Hooper on the casualty list.

However, Saints hope to have Jon Wilkin, who has missed the last four games with a hand injury, back for Saturday's game against Wigan.

Teenager Stephen Tyrer will continue to deputise for winger Ade Gardner, who is still sidelined with an eye injury.

"Jon Wilkin will be in the 20-man squad and we'll make a decision on him later in the week," said Saints boss Daniel Anderson ahead of Saturday's game, which will take place at the Millennium Stadium.

Wilkin, who was in the St Helens team that beat Wigan 32-16 to lift the Challenge Cup at the Millennium Stadium in 2004, admits he is desperate to play on Saturday.

"It would be fantastic to get back for the Wigan game," he said. "Walking around the stadium last week brought back memories of 2004 - we got a good result against Wigan that day.

"We've been disappointed with some aspects of our game. Our away form has been talked about recently and it's been a frustrating time for me personally.

"But, watching the lads, I've learnt a lot and maybe I can help with some of the shortcomings I've seen over the last few weeks."