Saracens have re-emerged as the greatest threat to Leinster’s European Champions Cup crown

And perhaps most worryingly for their rivals, they have not come close to hitting top gear yet

Saracens' Sean Maitland celebrates with Alex Goode after scoring against Cardiff (Reuters)

It feels as if Saracens are set to flex their collective muscle.

Twenty-one games unbeaten in all competitions, three wins from three in Europe and an increasing likelihood they will sign Wasps’ unsettled British & Irish Lion Elliot Daly next season, leaves Saracens in perfect shape heading into Christmas.

For their rivals, there is much to both fear and admire.

Another victory on Saturday against Cardiff Blues, who they dispatched with something to spare after a first-half wobble at Allianz Park last weekend, would see Mark McCall’s men take a vice-like grip of Pool Three of the European Champions Cup, with an away trip to Lyon and home visit of Glasgow to come.

With nine wins from nine in the Gallagher Premiership, it is all shaping up rather nicely for the north London club.

The bookies may make Saracens heavy odds on favourites, but victory at Cardiff Arms Park on Saturday, where the synthetic pitch at least will make it feel like home, is far from a given.

Blues are expecting their biggest crowd since last year’s Challenge Cup semi-final victory over Pau, while the return of talismanic back-rower Josh Navidi provides a much-needed boost to a squad director of rugby John Mulvihill admitted was “running on empty” by the final whistle last Sunday.

A six-day turnaround is just about the last thing Mulvihill and his backroom team needed – let alone their overstretched players – and the side he picked to face the two-time champions in London last reflected a need to manage resources ahead of the return fixture.

Even without the injured flanker Ellis Jenkins, scrum-halves Tomos and Lloyd Williams and playmaker Jarrod Evans, Saracens can expect to face a different Blues to the one which folded on Sunday after taking a surprise 18-13 half-time lead.

But following back-to-back defeats to Glasgow and then Saracens, it feels as if Blues’ first foray into the Champions Cup since 2014 has begun to run out of steam.

Saracens begin the game in bullish mood in a week when McCall revealed his club’s interest in securing Daly’s services next season, should he trigger a release clause in his contract allowing to move on if Wasps fail to build a long-overdue training ground.

Mako Vunipola put in a man-of-the-match display against Cardiff (Getty)

Already possessing a squad already dripping with international class, and enough relatively peripheral players leaving or retiring at the end of the season, there should be scope to accommodate Daly’s lofty salary ambitions without blowing the salary cap.

With Daly’s Lions team-mate Liam Williams already in situ, adding the 26-year-old flyer to their playing roster would add even more depth to one of Europe’s most potent pools.

With Maro Itoje also closing in on agreeing a contract extension and McCall himself settled and on a long-term contract which will warn off interest from potentially interested national governing bodies, Saracens appear to be getting ready to go deep in the Champions Cup again after a tough post-Lions season last year saw them knocked out by eventual champions Leinster in the quarter-final.

That was the last game McCall’s men lost, back on 1 April, and it would surely be a fool who bet against them finishing winners of Pool Three and powering into the knockout stages of Europe’s premier club competition.

George Kruis returns to Saracens second row against Blues after he was injured on England duty in the autumn while Ben Earl starts at No8 in place of Jackson Wray, Nick Tompkins partners captain Brad Barritt in the centre and Ben Spencer replaces Richard Wigglesworth at scrum half. None of the changes weaken Saracens one jot.

With nearest rivals Exeter suffering a significant blip domestically and in Europe in recent weeks, McCall’s men appear to be pulling clear on every front.

Perhaps most worryingly for their rivals, they have not come close to hitting top gear yet.

“We are where we want to be in terms of the tables, but we aren’t where we want to be in terms of our performance,” Saracens director of rugby said after seeing his side run in six second-half tries against the Blues. “We have had glimpses, but we have a lot of work to do still.”

Critically, by winning so many games before Christmas in Europe and domestically, McCall will be able to rest his most heavily worked players – the currently injured Itoje among the most notable – as the business-end of the season approaches.

While other clubs will be scrabbling desperately for wins, and their players suffer accordingly, Saracens should be able to freshen up their squad, safe in the knowledge they have done the hard yards early.

Precisely what fruit all that hard work will bear come the end of the season remains to be seen but one thing is crystal clear; two-time champions Saracens have re-emerged as Leinster’s greatest threat to their European crown.