Spain midfielder Xabi Alonso believes his team will need to be at their best if they are to defend their European title.
Vicente del Bosque s men, the reigning world and European champions, enter the tournament in Poland and Ukraine as favourites.
But Real Madrid playmaker Alonso said his side face a difficult task to secure back-to-back titles.
It gets harder and harder to continue winning, Alonso told GQ.
We have a good team, we have the experience, but there are also other teams who are well prepared and very eager.
I think it will be even harder than Euro 2008 and World Cup 2010, because we will have to be almost perfect to win the title.
Despite tense recent encounters between La Liga giants Real Madrid and Barcelona, Alonso said the atmosphere in the national team was calm.
That is something different and has nothing to do with what goes on in the national team, he said.
When we are with the national team, especially in a major international competition and when we are fighting for something like this, it does not matter the way the season ended.
If someone won something, you congratulate them, if you won something, they congratulate you, but you are fighting for something else here.
