5 Key Battles in Matchday 4 of the European Rugby Champions Cup

This weekend brings a second successive week of continental action, where the European Rugby Champions Cup will once again head into the fray with qualification edging into sight.

Last time out, Clermont Auvergne and Harlequins claimed crucial advantages over their pool opponents with victories over Munster and Leinster, respectively, but the same foes are back for revenge this week.

Read on for a rundown of which battles are likely to have a big hand in picking out the victors on Matchday 4.

1. Rob Kearney vs. Mike Brown

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An off week for Rob Kearney at The Stoop was a contributing factor in Leinster's demise at the hands of Harlequins last week. His sloppy pass directly led to Alesi Tikoirotuma grabbing an 80-metre run-in try.

The blame, of course, can't be lumped solely on Ireland's No. 15, who on his day can influence a fixture in offering domineering aerial ability and a welcome, catalytic option in the line.

However, he faces England counterpart Mike Brown in Round 2 of their head-to-head on Saturday and has no choice but to turn out a much more flexible performance in the Irish hosts are to succeed.

Brown didn't beat as many defenders as his opposite number in the first leg (his five to Kearney's six), but his 80 carrying metres were more than twice that of what Kearney managed.

Each regarded as potentially stubborn characters in defence, Leinster will look to reclaim a step in the Pool 2 race with victory at the Aviva. However irresponsible it may sound, it could be the fullback who's willing to step outside their comfort zone and take risks who prevails.

2. Jamie Cudmore vs. Paul O'Connell

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A second meeting between Jamie Cudmore and Paul O'Connell this Sunday whets the appetite nicely for what promises to be one of the most entertaining fixtures of the entire European schedule.

Munster will be left feeling sore after managing to take just a bonus point from last week's 16-9 defeat at Thomond Park, but O'Connell is a figure who embodies the fight that makes the club such a force in this competition.

The Munster captain was a reliable figure at the line-out during that loss, but Cudmore's presence in the loose stood out more, particularly with his 16 tackles displaying a vitality far greater than his 36 years might suggest.

The veteran second rows will come together for another rendition of their fiery encounter, where brutes with brains will have a dramatic impact on who takes the reins in Pool 1.

3. Sam Burgess vs. Wynand Olivier

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ESPN Scrum confirmed on Thursday that Sam Burgess would make his full Bath debut against Montpellier on Friday, ready to start alongside Jonathan Joseph in the centre.

Mike Ford's men were unfortunate not to get a bonus-point win on their trip to the Altrad Stadium last weekend, but Bath can continue their Pool 4 revival at The Rec this time around.

Wynand Olivier will have the assuredly painful honour of being the first man to start opposite cross-code marvel Burgess, where confidence will be key in combating England's current man of the moment.

Should he fail to assert his own offensive threat, Montpellier's inside centre risks regressing into an exclusively defensive role, where welcoming Burgess to run at him isn't likely to end well.

Burgess will take pleasure in multiple-man coverage—such is the force he brings to midfield. However, it's his playmaking skills that will draw most attention in order to capitalise on that freed space.

Everyone knows he can play the part of a wrecking ball; now is his first chance to prove he's something far more intuitive.

4. Carl Hayman vs. Marcos Ayerza

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In a sharp turn of events, Martin Castrogiovanni looks set to miss out on the home leg of Toulon's tie against Leicester Tigers and will most likely be replaced by Carl Hayman for Saturday's fixture.

An expletive-ridden rant from the Italian in the wake of last weekend's loss at Welford Road has resulted in Toulon suspending the player for three days, according to the Telegraph's Daniel Schofield.

Toulon owner Mourad Boudjellal is quoted in saying:

"

I was very surprised by Martin’s behaviour. This is not the boy I know. It was clear that he was disappointed, but he used bad language. I did not expect that. We are sending Leicester and Richard Cockerill a letter of apology and I will be meeting the player with Bernard Laporte decide whether to take any action. Some form of sanction cannot be ruled out.

"

Despite Castrogiovanni's grievances for the manner in which he left Leicester or his feelings toward former coach Richard Cockerill, Hayman is no minor replacement to face Marcos Ayerza, although the change is still significant.

In a 30-minute cameo last weekend, Hayman managed to make six tackles and looked a fresh figure, but it's the scrummaging impact that could prove substantial.

Ayerza will look for an improved performance in the loose and hope that a more secure set piece can be achieved, having lost two of their eight scrum put-ins en route to a 25-21 victory last time.

Hayman brings with him a similarly experienced skill set as Castrogiovanni, with his team-mate's absence providing a stellar opportunity for the New Zealander to make a quick impact.

5. Andy Goode vs. Daniel Kirkpatrick

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Even in his old age, Andy Goode is showing the ability to dictate a tie with extreme efficiency, such was his influence in an inspired 32-17 win at Castres last weekend.

The Wasps fly-half slotted five of a total six kicking attempts to give his team a reliable thrust in what was a pivotal result if they're to advance from Pool 2, but there are areas which can be improved.

Castres counterpart Daniel Kirkpatrick at times made the 34-year-old look sloppy in defence, and when coming up against a fluid running motion, Goode can be made to show his age.

In order to play at his optimum, the Wasps puppeteer requires time and can still conjure up magic when that's the case, but a strong pack outing on Sunday will be key in that pursuit.

All statistics come courtesy of ESPN Scrum.