Few would have bet against Spain reaching the semi-finals of the FIFA Confederations Cup South Africa 2009 but the identity of their last-four opponents has surprised everyone. Not even the most optimistic of USA fans would have tipped Bob Bradley's team for a place in the knockout phase after they lost both their opening games in disappointing fashion. Yet the Americans whipped up a perfect storm in the final round of games in Group B on Sunday 21 June to snatch second place in the section from Italy and Egypt.

The Spanish can be excused for welcoming USA's unexpected presence at this late stage. After all, before the tournament started the European champions were bracing themselves for a stern semi-final test from reigning world champions Italy. But now that the CONCACAF Gold Cup holders have negotiated their way out of a fiercely competitive group, Spain would be well advised to treat them with maximum respect.

The match
Spain-USA
Free State Stadium, Mangaung/Bloemfontein, 24 June, 20.30 (local time)

After making several changes for the final group game against South Africa, with every member of the squad bar third goalkeeper Diego Lopez having enjoyed some playing time, Vicente del Bosque will field his strongest line-up once more. Iker Casillas returns in goal, determined to chalk up Spain's fourth clean sheet of the competition, while Xabi Alonso and Xavi will reclaim the central-midfield reins. Up front the deadly twosome of David Villa and Fernando Torres will continue their private duel for the adidas Golden Shoe.

In contrast Bradley has plenty of selection issues to ponder. His decision to hand starts to goalkeeper Brad Guzan and forward Charlie Davies paid off handsomely and the US coach will surely be tempted to keep faith with them, while also considering the role of Clint Dempsey, who made a decisive contribution against the Egyptians as an attacking spearhead.

Key battle
Landon Donovan vs. Xavi

This pair of talented performers set the tempo for their respective teams and the outcome of this particular contest will go a long way to deciding the game. Donovan has been one of USA's most active midfielders in the tournament to date, completing 125 passes (a success rate of 65 per cent), firing in four shots on goal and scoring once. Xavi is the pass-master supreme, however, making 258 passes in all (an 89 per cent completion rate), though he has yet to provide an assist or score a goal in South Africa. Both sides depend heavily on their creativity and the two are sure to have a big say in who comes out on top on Wednesday evening.

Looking back
Spain 3-1 USA, 25 June 1950, 1950 FIFA World Cup Brazil™, Curitiba

La Roja have never lost to the Stars and Stripes. The most important of their three previous meetings came at Brazil 1950, where Spain finished fourth, their highest-ever placing in the competition. This victory over the Americans came in the group phase, with a brace from Estanislao Basora and a goal from the legendary Telmo Zarra cancelling out John Souza's opener for USA.

The stat
0.66 - The average number of goals David Villa scores every time he pulls on the red of Spain. The Valencia hitman is the second-highest scorer in his country's history, having hit 31 goals in 47 appearances. Leading the way is Raul, who nevertheless has an inferior strike rate of 0.43. Only two players who have scored over 20 goals for La Roja boast a better goalscoring average than Villa: Zarra, with 1.0 (20 goals in 20 games) and Alfredo Di Stefano with 0.74 (23 goals in 31 games).

Did you know?
Wednesday's meeting between Spain and USA will be a special occasion for Jozy Altidore, who signed for Villarreal last year but spent the second half of the season on loan at Xerez. The big American striker will be returning to the Yellow Submarine for the upcoming league campaign, where he will team up once more with Spain squad members Joan Capdevila, Santi Cazorla and Diego Lopez. Which of them will be smiling when the final whistle blows at the Free State?

The quotes
"It's always tough to win when you're the favourites. We'll need to work hard to reach the final," Spain defender Gerard Pique.

"We came up against Spain before EURO 2008 and we played a great game. We've been watching them during this tournament and we've been taking note of their style. We know how to stop them and we are very confident," USA coach Bob Bradley.

Have your say
Do USA have the firepower to spring another surprise? Will the CONCACAF representatives get the better of their UEFA counterparts in this intriguing semi-final duel? Click on ‘Add you comment' and let us know your opinion.