Bulls coach Mick Potter has revealed new recruit Manase Manuokafoa will be sidelined for at least two months by a knee injury.

The Tonga international, signed from Parramatta on a one-year deal, tore the posterior cruciate ligament in his knee during a training session towards the end of last week.

He was subsequently ruled out for a minimum of eight weeks and will therefore play no part in the opening month of the new Super League campaign.

Potter – speaking after yesterday’s 28-18 pre-season friendly defeat at Castleford – said: “Nas has torn his posterior cruciate ligament, which is an eight to ten-week injury.

“He’s in a brace at the moment, so there is no operation required and it will heal itself.

“He would have played against Castleford but for the injury, even if it wasn’t the full hit-out.

“He hasn’t played since early September so it would have been good for him to be involved in some way.

“But now we will have to wait for another couple of months. It’s obviously very disappointing for everyone, not least to Nas himself.”

Explaining how the giant front-rower sustained the injury, Potter added: “It happened during a contact in training.

“We have to do it and it’s just unfortunate. It’s one of those when you get a few bodies coming together in contact and they get twisted the wrong way.”

Potter watched his youthful side score four tries but concede six at the PROBIZ Coliseum yesterday in their first pre-season friendly ahead of the 2012 campaign.

Trialist prop Phil Joseph led from the front in the pack and there were some encouraging signs from the Bulls’ young guns, notably John Bateman and Adam O’Brien.

Yet Potter admitted that there was still plenty of work to do before the season-opener at home to Catalan Dragons on February 5.

“Our structure defensively could have been better and that comes from a lack of communication and maybe a bit of fatigue setting in,” he said.

“We started well in both halves and just let ourselves down with a couple of penalties for obstruction.

“There were a couple of things that were avoidable but in the heat of battle we got them wrong.

“But I thought there were enough promising signs there and some of the young guys were very good.”