GROUP B/The Permutations: Raul has not spent sleepless nights studying videos of Gary Breen, and Juan Carlos Valeron must know little about Mark Kinsella. But while a superficial assessment suggests Spain would ease past the Republic of Ireland in their probable second-round meeting on Sunday, there is plenty to give hope to Mick McCarthy's side, writes Jon Brodkin in Seoul

Spain have already booked a last-16 place and will be Ireland's opponents if their much-changed team avoid defeat today by South Africa, the other possible group winners.

Ireland would have to contain Raul and Fernando Morientes, no easy task. The £120m buy-out clause in Raul's Real Madrid contract means he is valued at more than the Republic's XI combined. Yet if Breen and co can keep Spain's attack in check, there are weaknesses that could be exploited.

The centre-back pair of Fernando Hierro and Miguel Angel Nadal look susceptible to the speed and direct running of Robbie Keane and Damien Duff. At 34 and 35, they are more vulnerable than ever; Spain have not kept a clean sheet so far.

Against Slovenia the centre-halves struggled against the pacy substitute Sebastjan Cimirotic, who ran at them, scored a goal and had two - probably unjustified - penalty appeals turned down.

When Hierro was outstripped in a short sprint by Paraguay's Roque Santa Cruz, the problem resurfaced.

The striker failed to provide the killer cross, but passes into the space between full back and centre-half could be effective. Behind them, Iker Casillas has looked uncomfortable on crosses.

Spain's talent in midfield is undeniable, with Valeron a particular danger, and allowing them good possession is unthinkable. Yet they were initially hurried out of their stride by Slovenia and struggled for 45 minutes against Paraguay. Given the heat in Suwon, Ireland will be helped by an 8.30 p.m. kick-off local time.

A key challenge for McCarthy is to find the correct balance on the right flank, where Spain can be exposed because their left midfielder Javi de Pedro looks a graduate of the David Ginola school of defending. But De Pedro is dangerous coming forward. His perfect cross set up Valeron's goal against Slovenia and he also provided the centre for Morientes' second against Paraguay.

Morientes today seems certain to retain his place ahead of Diego Tristan. Ireland might prefer Morientes, whose game is built more on strength than the subtlety Tristan can produce at his finest. Yet the Real striker is in form and enjoys a club understanding with Raul, whose willingness to drop deep would have to be monitored. This pair are expected to feature against South Africa, though the team will probably show five other changes.

South Africa looked poor despite beating Slovenia. If Jomo Sono's team grab an unexpected win, Ireland can surely look forward to the quarter-finals.

Against Spain the job would be trickier, and penalties may offer their best bet. But it is no impossible task.

Cesare Maldini is doing his best not to fret publicly but Paraguay's coach is clearly a worried man.

Rumours from Spain's camp that they may rest their best players against South Africa today have done little for Paraguayan nerves as they seek to sneak into the second phase. "It's out of our hands," sighed Maldini.

The South Americans, with a solitary point, must run riot against Slovenia today and hope Spain win. Not that Paraguay will throw caution to the wind. "We need to score goals, and plenty of them, but our approach must be the same as always," said Maldini.

However goalkeeper Jose Luis Chilavert described the match as "a matter of life or death".

Guardian Service

• Spain will finish first and play the Republic of Ireland if they avoid defeat against South Africa

• South Africa must beat Spain to finish first. A second-place finish will see them play Germany in the next round

• Paraguay, with an outside chance of second spot, need a convincing win over Slovenia and hope Spain beat South Africa

• Slovenia's match with Paraguay will be their last of the tournament