England take on Italy on Sunday in what promises to be the tightest of the Euro 2012 quarterfinals. It is a battle of two sides in transition, with fewer expectations than in many past major tournaments. Some fine margins are likely to decide who reaches a semifinal with Germany. Here are five things that could make the difference.

Three or Four at the Back?

Cesare Prandelli's decision to go with three at the back worked a treat against Spain and for the opening half against Croatia. A more conventional four returned against Ireland and the team produced arguably its least assured performance so far. Giorgio Chiellini's injury in that match will cause Prandelli further headaches as he ponders over his lineup to face England.

It seems likely that Leonardo Bonucci will come into partner his Juventus club-mate Andrea Barzagli in a four man back line. The two formed an impressive partnership in helping the Old Lady to the Serie A title last season and, although not the quickest, should ease the absence of Chiellini. The challenge will be finding a cohesive blend with what will be a narrow four-man midfield.

Welbeck or Carroll?

Both strikers scored in the 3-2 win over Sweden, but it was Andy Carroll who made way as Wayne Rooney retuned from suspension against Ukraine. Each man offers something different. While Carroll provides the power and ability in the air of a traditional English center forward, Danny Welbeck possesses pace and an increasing ability to link up well with those around him.

Given a far from rapid Italian backline, Welbeck is likely to be given the nod. He will not only have to threaten in behind but also be effective in holding up the ball.

Midfield Battle

If Italy elect to go with four at the back then that means Daniele De Rossi reverting to his more familiar midfield role. A move that will bring him face-to-face with a man he has described in glowing terms in recent days, Steven Gerrard. The Liverpool talisman has been the standout player for England so far, as he has been able to add tactical discipline to his impressive range of passing.

But England's midfield has been caught too deep on occasion in this tournament and there is reason to believe that they will struggle to prevent Italy's center gaining control. De Rossi is a formidable presence and will be accompanied by the exemplary passing of Andrea Pirlo. With the likes of Claudio Marchisio sure to be constantly on the move, breaking from deep, England could struggle to cope.

Wildcard Balotelli

Mario Balotelli has become a topic of conversation over which everyone seemingly has a say. What was a simple missed opportunity as Sergio Ramos got back and challenged him against Spain became something of a scandal.

He may have the ability to self-destruct, but he is still young and is first and foremost a terrific striker. Against his Manchester City teammates Joleon Lescott and Joe Hart, as well as the nation in which he plies his trade, he may just remind everyone of why his Italian boss Roberto Mancini continues to tolerate the maverick front man.

England's Defense

When a side is set up to invite pressure, their defense needs to possess the organization, concentration and defensive nous to soak it up. For England, major question marks remain over their competence in all three areas.

The two goals conceded in quick succession against Sweden were inexcusable gifts. Glen Johnson was caught out badly for the first and he remains a player whose defensive qualities don't come close to matching his attacking ability. Antonio Cassano, who excelled against Spain drifting into the space left by the right-back, could be poised to exploit Johnson's weaknesses. In the middle, alongside John Terry playing out of position on the right, Joleon Lescott lacks the concentration to be considered a truly international class defender.

It is the defense that could well prove England's downfall in a closely-fought encounter.