Both sides have only managed to score once in their first two games but Spain have one more point than Argentina, who currently sit third behind Australia on goal difference.
Having seen a large proportion of possession in their favour, Spain have also been able to limit their opponents to few chances on Unai Simon's goal, and they are the only nation who are yet to concede at the Olympics this summer.
The Tokyo Games is only Spain's second appearance at the Olympics since 2000, most recently they were eliminated at the group stages at London 2012, but the nation has previously won this competition at home in 1992.
Avoiding defeat on Wednesday will secure Spain's place in the last eight, but to top the group and not rely on the result in the game between Australia and Egypt, they need all three points.
Argentina need to play catch-up on Wednesday after one win and one loss at the Olympics so far this month, and even a win against Spain will not make their place in the quarter-finals certain.
Fernando Batista's side will need to better Australia's result against Egypt, and if the Aussies win Argentina will have to beat Spain by a big margin to overturn a two-goal difference gap.
Their Tokyo Olympics campaign did not get off to a great start when Australia's Lachlan Wales scored inside the first 15 minutes in their opening fixture, and the situation for Argentina worsened when Francisco Ortega was shown a second yellow card before half time.
Argentina scored with their only shot on target in their last outing when they faced Egypt, centre-back Facundo Medina getting his side off the mark with that goal on Sunday.
The South American side are looking to better their group stage finish in Rio 2016, when the four points they earned eliminated them from the Olympics, and the side will be taking inspiration from the Argentinian squads that won gold in 2004 and 2008.
Spain have no injury or suspension concerns ahead of Wednesday's fixture, with many of their players into their second international tournament of the summer having represented Spain at the Euros.
Pedri has been an ever-present for De la Fuente's side at the Olympics this summer, but the pair who line up with him in midfield have altered in the opening two matches this summer - Mikel Merino and Dani Ceballos started against Egypt but were replaced by Carlos Soler and Martin Zubimendi in the last game.
Argentina's Ortega served his one-match suspension when his side played Egypt on Sunday, and he could be kept out of the starting 11 by Claudio Bravo, who played well last time out when he came into the lineup in Ortega's absence.
Batista went for a more attacking formation against Egypt and as they need to better Australia's result on Wednesday, he is expected to send out the same 11 to the side that picked up three points on Sunday.
Spain Under-23s possible starting lineup:
Simon; Cucurella, Torres, Garcia, Gil; Zubimendi, Soler, Pedri; Olmo, Oyarzabal, Puado
Argentina Under-23s possible starting lineup:
Ledesma; Bravo, Medina, Perez, De La Fuente; Vera, Payero; Barco, Allister, De la Vega; Gaich
We say: Spain Under-23s 1-1 Argentina Under-23s
Spain are likely to dominate the possession again on Wednesday which is likely to limit Argentina's chances in front of goal, and having only scored one goal in this tournament so far, it is unlikely that they will manage any more than a single goal against Spain.
The Spanish have not been free flowing on the scoring front either, meaning that this game could be one of few goals and is expected to be a tight affair.
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