Spain coach Vicente del Bosque admitted he is unsure who will start Monday's Group D opener against Czech Republic, though De Gea got the nod ahead of veteran Iker Casillas in Tuesday's shock 1-0 friendly loss to Georgia.
Despite his appearance at the Coliseum Alfonso Perez, De Gea does not know if he will take to the field for the two-time defending European champions in Toulouse.
"We'll see what happens on [June] 13. I'm here to do what the coach tells me," the 25-year-old said post-match.
"When I'm on the pitch, I only think about helping the team and doing well. We mustn't dwell on this result.
"I'm here on the back of three good seasons for Manchester United.
"There's always debate about the goalkeepers, but us three will do our best."
De Gea enjoyed another fine Premier League campaign for United, keeping 15 clean sheets.