DALE McIntosh has warned his Cardiff Blues charges that they risk being sent 'flying to Risca' if they get it wrong in defence against Newport Gwent Dragons ace Taulupe Faletau at Rodney Parade on Saturday.

The Wales number eight is poised to return to the starting XV for the European Rugby Challenge Cup quarter-final derby (kick-off 12.45pm).

The Dragons are blessed with back row options but Faletau, who has played every minute for Warren Gatland's side since November, 2013, is undoubtedly their dangerman.

Blues forwards coach and Pontypridd icon McIntosh, who knows a thing or two about big hits, knows they must get to grips with the 24-year-old.

"Toby is huge and is a world class player," said McIntosh. "Although we can't focus on one player we need to pay attention to him, especially when he has got ball in hand.

"He is destructive and, although we can't go out of our system to look after him, when we do make contact with him we have to make it count otherwise you'll end up in Risca.

"Toby is a class act, he doesn't say a lot but what he does is uplifting as far as the Dragons are concerned."

Faletau's return could push Nick Crosswell out of the XV, although the New Zealander has previously played Super Rugby at openside and could be an option if flanker Nic Cudd fails to overcome a neck injury.

James Benjamin is the other candidate at 7 while 20-year-old flanker Ollie Griffiths, Wales' star of the Under-20s Six Nations, is not registered in the Dragons' European squad.

The Blues will be without fly-half/full-back Rhys Patchell and centre Cory Allen for the clash after they suffered a concussion and shoulder injury respectively in last Friday's loss to Ulster in Belfast.

They will, however, be boosted by the return of loosehead Gethin Jenkins after his recovery from a hamstring problem that forced him off against Ireland in the Six Nations, leading to him sitting out the tournament finale in Italy.

McIntosh is thrilled to have the help of another senior figure as the Blues get used to life without Mark Hammett, who left his role as director of rugby in February for personal reasons.

"Gethin is training really hard and is enthusiastic," said McIntosh. "We are down coaches at the moment with myself and Paul (John, backs coach) at the helm and he has really stepped up, helping me out with defence and individual stuff. He has been huge this week."

The Dragons beat the Blues at Cardiff Arms Park on Boxing Day in the Guinness Pro12 before the tables were turned at Rodney Parade on New Year's Day.

Their shock success in the capital was down to a snarling effort at the breakdown and a well-drilled linout that led to a score by hooker Elliot Dee and a penalty try.

McIntosh insists that the Blues aren't vulnerable to the driving maul, one of the Dragons' most potent weapons this term.

"We were poor (on Boxing Day) and our psyche wasn't good enough – we disrespected ourselves by disrespecting the Dragons and we got exactly what we deserved," he said.

"If we do that again we will get the same, but we don't make the same mistake twice.

"We've been pretty good defending driving lineouts all season. It's not a weak point, we just got it wrong on the day."