England vs. Ireland: 5 Key Battles in International Match

Two of Europe's top contenders for the Rugby World Cup clash at Twickenham on Saturday, when Ireland will attempt to topple their English hosts in the battle for a substantial pre-World Cup morale boost.

Head coaches Stuart Lancaster and Joe Schmidt have named their teams for what will be each side's final warm-up fixture prior to this year's big kick-off on September 18.

The squads for the tournament have been named, and both sides have put forth some interesting player selections for the London encounter in which stars from both sides will be looking to cement their spots in the lineup.

Performance is what will matter most in this head-to-head of old rivals, with a host of Saturday's key battles dissected further ahead.

1. Brad Barritt vs. Robbie Henshaw

Injured at the time of their defeat to Ireland at the Aviva Stadium six months ago, England's Brad Barritt was nowhere to be seen, but he'll hope to prove the difference this time around.

And it just so happened to be that Robbie Henshaw, Barritt's opposite man on Saturday, scored a terrific takedown try to make the difference on that occasion.

Barritt has risen to become an undebatable selection for Lancaster as far as some will be concerned, but he and Jonathan Joseph have had little time to perfect their midfield relationship.

According to the Telegraph's Mick Cleary, Joseph said England's first-choice centres have been working hard, however, and will be ready come the World Cup: "I feel very confident playing outside of Brad as we have done a lot of work in training, interchanged and done lots of work in the analysts room that ties everything together. I feel we can have a good relationship there."

Ireland midfielders Henshaw and Jared Payne are also still getting to grips with one another after less than a year combining properly, making Saturday's midfield battle particularly intriguing.

2. Ben Morgan vs. Jamie Heaslip

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It went down to the wire, but Ben Morgan got the nod over Nick Easter in England's selection, and the No. 8 faces an instant test in his bid to prove his full fitness with Ireland's Jamie Heaslip blazing in his direction.

Christopher Jones of BBC 5 Live quoted England forwards coach Graham Rowntree as saying Morgan's fitness isn't a concern, and one would hope that's the case with such a fierce fight on his hands against Ireland.

Heaslip was a mauling influence in the 35-21 win over Wales at the Millennium Stadium in August, but let's not forget Morgan actually sat above No. 8 contender Billy Vunipola in the England pecking order prior to his injury.

Both figures add a great deal of structure to their respective packs, depending on which side can get its angles right, but a war between two titanic carriers of the ball will also be a sight to watch.

3. Anthony Watson vs. Dave Kearney

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A whirlwind 12 months for Anthony Watson has seen the Bath marvel emerge as one of Lancaster's standout options on the wing, but Dave Kearney brings with him the potential for a stern examination on Saturday.

Watson recently grabbed a brace in England's 19-14 win over France at Twickenham, but even that superbly clinical display isn't going to his head, as he said more is needed to tie down his place, per Sky Sports:

"

I'm looking to seize this opportunity with both hands. I've watched my tries a few times, I wouldn't say over and over because all that stuff doesn't really mean much unless you do it again. Performing at international level is about doing that week-in week-out and not having inconsistencies.

All three wings have been going well. Jonny [May] played particularly well in the first France game and showed what he can do in the second Test against France as well. For Jack [Nowell] to beat 10 defenders in Paris was a special feat. All of us are challenging each other and trying to make each other better.

"

It's that type of hunger that will undoubtedly serve the speedster well as he jostles against stiff competition, but Kearney is another who knows his spot in Schmidt's XV is far from certain.

The Leinster man finds himself in the Ireland squad after impressing thoroughly in the 16-10 defeat to Wales in which his performance was one of the positives for Ireland despite that result.

Pace is an obvious common denominator between the two, but it's likely Saturday's head-to-head will rest more firmly on whom can be caught out positionally, with no small help from their respective fly-halves.

4. Courtney Lawes vs. Paul O'Connell

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The old saying of the unstoppable force and the immovable object comes to mind when envisioning an encounter between Courtney Lawes and Paul O'Connell, two unrelenting powerhouses of their position.

Lawes has taken little time to settle back among the English locks as he regains full fitness, shining as one of the few bright spots during his side's 25-20 defeat to France in Paris in August.

O'Connell makes for an interesting figure to watch at this year's World Cup, looking to bow out of his international days on a high and most likely summoning an eerie source of his own strength.

Aside from the evident threat both players carry at the lineout, Lawes and O'Connell are two of Europe's more mobile second-rowers, making their contribution in the loose come Saturday that much more significant.

5. George Ford vs. Johnny Sexton

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The time has come to stop wrapping players up in cotton wool ahead of the World Cup, as Lancaster and Schmidt roll out their big guns to pit first-choice fly-halves George Ford and Johnny Sexton against one another on Saturday.

And while Sexton's place is assured at No. 10, England counterpart Ford faces more of a fight to stave off competition from Owen Farrell, someone Lancaster says is playing his best rugby, per the Telegraph's Cleary:

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It is tight. Owen is back to his very best, in terms of his defence, his kicking, his game management and his attack. It is the best I have seen from him and he is pushing hard.

It is positive competition. I don’t need to put heat on George about the position. He trains against Owen each and every day. I have a lot of faith in him. He was exceptional for us in the Six Nations. But this is a big game for him because Ireland have a very good kicking game and our kicking has to be spot on.

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Of course, Farrell's gazing shadow is no new pressure to Ford, but an imminent World Cup makes his burden that much greater. Ford is still just 22 years of age, so the nerves may show at Twickenham.

It's make-or-break time for the Bath playmaker, who'll be hoping to disrupt the conductor-like Sexton enough while pulling some strings of his own to tie down a starting place in the England setup.