"Oliveira has not had a lot of minutes in the league for Benfica but he was in the league cup and his characteristics are different from those of all other strikers available, Helder Postiga, Hugo Almeida and Nuno Gomes," Bento told journalists on Friday.
The mobile 20-year-old striker, dubbed 'Portugal's Cantona', is a fans' favourite at Benfica though he has struggled to earn consistent first team starts at the club because of strong competition from Paraguay striker Oscar Cardozo and Spanish prospect Rodrigo.
"He could be one the players of the future of Portuguese football," Bento added, saying his good performances at the 2011 Under-20 World Cup in Colombia, where he scored four goals, were also behind the call-up.
"Many of the players chosen today will be at the Euros unless there is a last-minute unpredictability".
Portugal are in group B with the Netherlands, Denmark and Germany for Euro 2012, which Poland are co-hosting with Ukraine.
Goalkeepers: Rui Patricio (Sporting), Eduardo (Benfica), Beto (Cluj).
Defenders: Joao Pereira (Sporting), Bruno Alves (Zenit St Petersburg), Fabio Coentrao (Real Madrid), Pepe (Real Madrid), Nelson (Betis), Ricardo Costa (Valencia), Rolando (Porto).
Midfielders: Carlos Martins (Granada), Joao Moutinho (Porto), Manuel Fernandes (Besiktas), Miguel Veloso (Genoa), Raul Meireles (Chelsea), Ruben Micael (Zaragoza).
Forwards: Cristiano Ronaldo (Real Madrid), Hugo Almeida (Besiktas), Helder Postiga (Zaragoza), Nani (Manchester United), Nelson Oliveira (Benfica), Ricardo Quaresma (Besiktas), Silvestre Varela (Porto).
