Real Zaragoza's Helder Postiga, the usual starter, and Hugo Almeida of Besiktas are the only other forwards picked for the tournament. Portugal start their Group B campaign against Germany in Ukraine's Lviv on June 9 before facing Denmark and Netherlands in the most difficult pool of all.
"I have different characteristics from Hugo and Helder Postiga, the key ones are my speed and strength," Oliveira said.
He burst onto the scene at the last Under-20 World Cup where he scored four goals as Portugal reached the final.
The 20-year-old has since become a fans' favourite for Portugal and club Benfica.
"It all happened a bit fast but a top-level player has to deal with these situations," Oliveira told reporters before Portugal's first full-squad practice in the medieval Portuguese town of Obidos.
"It has been a pretty good year for me, starting with the Under-20 World Cup, then with my season at Benfica and culminating with my call-up to the Euros."
Critics say that while Portugal's midfield is world class and creates many chances thanks to the likes of Cristiano Ronaldo and Nani, their attack has been chronically wasteful.
Coach Paulo Bento has labelled Oliveira as Portugal's "future" and gave him his debut against Euro 2012 co-hosts Poland in Warsaw in February.
The squad will stay in Obidos until June 2 before leaving for Opalenica, their headquarters in Poland.
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