The 28-year-old striker, hero of Spain's triumph at the European Championship in 2008, has struggled since joining Chelsea from Liverpool in January last year but has a chance to rediscover his best form in Poland and Ukraine next month.
With record scorer David Villa ruled out through injury, Torres is likely to be in Del Bosque's starting lineup when they play Italy in their opening Group C match on June 10, something he said he would have found hard to believe in February when he was dropped for a friendly against Venezuela.
"I was left out of the squad and that was tough," Torres said at a news conference at Spain's pre-Euro 2012 training camp in Schruns, Austria on Monday.
"I started to understand that things were serious, that I wasn't getting much playing time with my club and that if things carried on that way I wouldn't be going to Euro 2012," he added.
"Vicente has put his faith in me and now I need to show him I am ready to play whenever he thinks it necessary. I hope to be able to give the team the best of me."
Torres, who has netted 27 times in 91 appearances for his country, said his reprieve had made him more enthusiastic than ever and he was fighting fit after spending a considerable part of season watching from the Chelsea bench.
"When you see yourself missing out and then you are selected you are more excited even than the first day," said the striker, whose club side lifted the Champions League earlier this month.
"I have arrived feeling fresh because I haven't had the same physical burden as the others and I am in good shape.
"I would have liked to have played more for my club but the important thing is that everything works out in the end."