Doubts over the fitness of Ukraine goal machine Andriy Shevchenko and question marks over Spain's strikers have dominated the build-up to today's clash between the two favourites to qualify from Group H.
Former European Footballer of the Year Shevchenko has been nursing a knee injury and his participation against Spain will remain in doubt until the last minute.
The 29-year-old scored as a substitute in Thursday's 3-0 warm-up win over Luxembourg and has looked sprightly in training but Shevchenko has suggested that he will not be fully fit until their second match against Saudi Arabia on Monday.
"I'm working with the squad and I'm feeling quite good," he said.
"This period is important for me as I have to work to get in better shape, possibly not for the first match but for the ones after."
Coach Oleg Blokhin could delay a decision on whether the striker plays in today's game until as late as one hour before kick-off.
Spain come into the World Cup with the longest unbeaten run of the 32 finalists, having gone 22 games since their last loss and their preparations appear to have gone like clockwork but the jury is still out on the form of their forwards.
Captain and all-time leading goalscorer Raul looks headed for a place on the bench after failing to rediscover his touch since a serious knee injury while Fernando Torres, David Villa and Luis Garcia are favourites to start up front. The trio have, however, only managed one goal between them in three warm-up games and despite their undoubted class have yet to show the necessary killer instinct.
Argentine-born defender Mariano Pernia should start at left back just a week after his goalscoring debut in a friendly with Croatia, while Marcos Senna, Xabi Alonso and Xavi look to be the first choice midfield.
After a history of World Cup disappointments, Spain's more down-to-earth approach this time could be their trump card.
"Historically, we haven't achieved good results at the World Cup," says coach Luis Aragones.
"It's hardly surprising that people don't have that much faith in us but the time has come to take it one game at a time and show how good we really are."
The 67-year-old is also keen not to underestimate his rivals even though they may be without their best player.
"Ukraine are not just Shevchenko," he said. "They have a lot of other class players and we will have a tough task stopping them."
Opposite number Blokhin has been more bullish about his side's chances.
"Of course, with Shevchenko Ukraine are one team but without him they are a completely different one," he said. "Am I worried? It's the Spaniards who should be worried."
If Blokhin starts without his captain, Ukraine's most capped player Serhiy Rebrov could partner Olexiy Belik up front.
Probable teams
Spain (4-3-3): 1-Casillas; 15-Ramos, 5-Puyol, 22-Ibanez, 3-Pernia; 16-Senna, 14-Alonso, 8-Xavi; 11-Garcia, 9-Torres, 21-Villa.
Ukraine (4-4-2): 1-Shovkovsky; 5-Yezersky, 6-Rusol, 17-Vashchyuk, 2-Nesmachny; 14-Husin, 4-Tymoshchyuk, 8-Shelayev, 21-Rotan; 11-Rebrov, 20-Belik.
Referee: Massimo Busacca (Switzerland).