Spain are expected to be without both Nico Williams and Yeremy Pino as they face Portugal for a place in the World Cup last-eight.
La Roja cruised to a 3-0 win over Austria in the round of 32, but are still carrying two injury worries from the group stage victory over Uruguay.
Williams was struck down with a groin injury, while Pino suffered a sprain to some ligaments in his shoulder.
A team statement released post-match read: “Both injuries are of moderate severity, and their recovery progress will determine their availability.”
Luis de la Fuente added, though, that both players were in danger of missing the rest of the tournament, while Williams described his re-injury as “one of the worst days of my life.”
Neither Pino nor Williams are regular starters for Spain, but De la Fuente will be frustrated to remain without two key rotation options.
As such, Barcelona’s Lamine Yamal and Atletico Madrid’s Alex Baena should keep their places on the flanks, with Mikel Oyarzabal through the middle. The Real Sociedad striker has as many goals as he does appearances so far this summer.
De La Fuente seems to have settled on a firm back five, with Marc Cucurella and Pedro Porro lining up either side of Pau Cubarsi and Aymeric Laporte. Unai Simon will keep his place between the sticks.
There may be a change in midfield after Dani Olmo and Pedri both struggled to impose themselves against Austria, with Fabian Ruiz waiting in the wings to step up.
Predicted Spain XI vs Portugal (4-1-2-3): Simon; Porro, Cubarsi, Laporte, Cucurella; Rodri; Olmo, Ruiz, Yamal, Oyarzabal, Baena
Injured: Williams (groin), Pino (shoulder)
How to watch: BBC Sport
Time and date: 8pm BST, Monday June 6.
Venue: Dallas Stadium