THE Ospreys are on the brink of a huge breakthrough – something absolutely magical – that could lead to them becoming the biggest and best club in the UK. All they have to do is win the Heineken Cup, and that starts with a quarter-final at Vicarage Road next Sunday, where they must beat Saracens, a side they crushed 30-3 in an EDF Energy Cup semi-final last weekend.

As a player, it is one thing to win a Grand Slam but to win silverware with your own club can be more rewarding, because these are the guys you pretty much live with for nine months of the year. The immense resources and finances behind the Ospreys, with big-name players on big salaries playing in a great stadium, look like being rewarded at last, with the team just three wins away from becoming the first Welsh club side to win the Heineken Cup, and match the national team in becoming champions of Europe.

With Mike Phillips ruled out with knee ligament damage for six months, they have lost a player who was on a roll, but Justin Marshall is a great scrum-half in his own right and was in outstanding form earlier in the competition. Champion sides get over injury setbacks and the Ospreys have depth. The front five of their pack play for Wales and the suggestion that it has a soft underbelly is rubbish. To get the better of an Irish pack at Croke Park requires guts, and the back row contains two fine ball-carriers in Ryan Jones and Jonathan Thomas, alongside Kiwi Marty Holah, who is arguably the best openside in the competition.

The quality ball they provide gives a star-studded back-line room to move, and a midfield trio of James Hook, Gavin Henson and Sonny Parker is a handful. Henson is playing the best rugby of his career, not just kicking goals but making breaks and doing the hard yards. He is making good decisions on a consistent basis.

Nikki Walker, Shane Williams and Lee Byrne are a mouth-watering back three. Byrne emerged from the Six Nations not just as a full-back with a big boot but with a reputation as being unflappable under the high ball, counter-attacking with ease and coming into the line with menace. He was one of the players of the tournament, as was Williams. Every time little Shane gets the ball in his hands you expect some magic.

Saracens may not be as overwhelmed as they were in Cardiff. They have a shrewd Aussie coaching duo in Eddie Jones and Alan Gaffney and have had plenty of time to not only work out a gameplan to clip the Ospreys’ wings, but to get over the loss of lock Chris Jack.

The Ospreys would be unwise to expect anything less than a fight. Players like Neil de Kock, Ben Skirving and Cencus Johnston are class acts, while Kevin Sorrell returns from injury to give shape to their midfield defence. In Brent Russell they have a broken-field runner who is almost as dangerous as Williams, and David Seymour can put down a marker as an international-class openside.

The ability of the Ospreys players cannot be questioned, but can they lift themselves to perform as they have done at Test level? From my own experience, it is tough after playing for your country and even harder after you’ve won a Grand Slam. The attention from the media is less intense, you have not been locked up in the team hotel for weeks and a different coach wants you to deliver in the same manner as at Test level. It is how successfully players adapt to these changes that make the team win or lose.

It’s never easy, but the great club teams of the past decade have managed to do it consistently. Wasps and Leicester have had stacks of players involved in winning Grand Slams and World Cups and those guys were able to put that to one side, pull on the club colours and win again.

The Ospreys players must create a legacy that will transform the Neath-Swansea amalgamation into a club with a real identity, one to rival the likes of Leicester and Munster. They must seize the chance to make the Liberty stadium as much of a fortress as Welford Road or Thomond Park, so teams are immediately at a psychological disadvantage when they draw the Ospreys.

Saracens v Ospreys, next Sunday, Sky Sports 2, 12pm, kick-off 12.30pm