Nick Easter today warned his Harlequins team-mates they face a major test against Ulster on Saturday as they look for the win which would clinch a place in the quarter-finals of the Heineken Cup.

Quins are unbeaten in Pool Four, having recorded a 42-21 home victory over the Irish province, an amazing double against big-spending Stade Francais, and a win over the Scarlets.

However, Quins have had a blip in the Guinness Premiership and Easter says his side have to rediscover the momentum that took care of Stade if they are to win both of their remaining games and guarantee a home quarter-final.

The England No8 said: "Since our Heineken Cup wins we have drawn one and lost two Guinness Premiership matches and now we face an Ulster side who are very different to the one we defeated at the Twickenham Stoop.

"They recently went to Munster and produced an amazing 37-11 away win and that will ensure we take nothing for granted in Belfast.

"No one is talking about needing just one more win to make the last eight because the aim is to get two victories because that is going to be needed for a home quarter-final.

"The Ulster team used a blitz defence against us and we were able to cause them problems but they are more organised at this stage of the season and the Munster victory proves so.

"They will be a lot better side and with rain predicted for the weekend there will be a lot of high kicks coming our way and it's going to be a big test."

Easter was unable to help Quins in their second-half fightback at London Wasps, who recorded a 24-18 victory with the No8 reduced to a hobbling spectator at pitch side.

He suffered a back spasm lifting at the line-out and this made it hard for him to walk properly for three days after the match.

"I haven't got any history of back problems and it was a muscle problem rather than anything structural," said Easter, one of the few England players to impress in the disappointing November Tests.

"I was ready to play against Worcester at home last weekend but it was called off due to the frost and we would have preferred to have a run-out.

"We wanted to get back to winning ways in the Premiership after those defeats and it was frustrating to be left without a game. The break has allowed us to work hard in training without any injuries to worry about and prop Ceri Jones is now fully fit for the Ulster game. We did have that winning habit which saw us triumph in Paris and again at the Twickenham Stoop against Stade and that's what we need to get back."

Quins will have to wait a little longer to see Dave Strettle (left) back in action following his third operation to repair a broken metatarsal in his foot.

The England wing has had bone from his hip grafted onto the problem area and now knows that last time he came back before the fracture had healed.

That mistake will not be made again, which means it could be two more weeks before he pulls on the multi-coloured jersey and bids for an England recall. Paul Steinmetz, the Ulster assistant coach, is talking up the Quins threat and said: "We are looking forward to facing them in Belfast as they are one of the English big guns.

"They are flying high and will want to come here and pick up the points.

"We have a proud record at home in the competition and we are very serious about this game. We want to come away with a win even though we're not in the running to make the quarter-finals.

"Generally, our defence has been getting better all season and we can take great heart from that."