Portugal coach Paulo Bento said his side had planned their penalty shoot-out strategy - and Cristiano Ronaldo was down to take the fifth spot-kick.
Reigning champions Spain beat the Portuguese 4-2 on penalties after a goalless draw, meaning Ronaldo did not have a chance to step up.
"We had this plan," the 43-year-old coach admitted after the semi-final.
"If it would have been 4-4 and he would have taken the last penalty, we would be talking in a different way."
Real Madrid star Ronaldo, 27, endured a frustrating evening, seeing a number of free-kicks sail harmlessly away from Spanish keeper Iker Casillas's goal.
He then watched in dismay as first Joao Moutinho's penalty was saved, then Bruno Alves hit the bar with his effort. Spain substitute Cesc Fabregas slotted home the winner to send Bento's men home and Spain into the final.
"It's always painful losing on penalties but penalties are always a lottery and the one who has the best luck wins," Ronaldo told the Portuguese newspaper O Jogo.
"It was a good Euro. We played the four best teams. We're going out a bit frustrated because we could have gone to the final but we were unlucky.
"I gave my best as I always have done and that's why I'm happy with my own contribution.
"We must be proud because we played well but we didn't have the luck we needed."
Alves's penalty miss was all the more acute as the defender had appeared set to take the preceding spot-kick before midfielder Nani rushed to intercept his team-mate.
Manchester United winger Nani scored his attempt but, following Alves's miss, Bento was left to regret the mix-up.
"There was some confusion with Bruno Alves and with Nani, then Bruno took the penalty... and it was decisive," the coach said.
"Penalties could have been an advantage for us."
The former Portugal international was left reflecting on a tournament that he regarded as a success, despite Wednesday's semi-final elimination.
"In my opinion we have played a very good tournament," he said.
"If you don't have this little bit of luck then you miss it. We didn't have much luck in this game."