Alvaro Morata considered leaving Chelsea this summer after calling his first season in English football "a disaster".
The 25-year-old striker joined Chelsea from Real Madrid last year and enjoyed a flying start with six goals in his first six Premier League games, but he struggled in the second half of the season, scoring just three times in the final 23 games.
The loss of form meant Morata missed out on Spain's World Cup squad and led to thoughts about leaving England in favour of a return home or to Italy.
"I thought about playing again in Spain or Italy. Of course I thought it would have been happy, but you cannot always escape from reality," he told the Spanish press.
"It was a disaster last year, I did not know where I was, I was not happy.
"I signed for Chelsea to be there (World Cup in Russia) and I was not, although that ultimately made me motivated.
"I do not hold a grudge against (former Spain coach Julen) Lopetegui, I've lived a lot of nice things with him too, it was his opinion and I did not do my best season either.
"But I do not hold a grudge against anyone, I wish him all the best and more now that he is at Real Madrid."
Morata, who has been recalled for the UEFA Nations League games against England and Croatia, admitted he took his international career for granted and was left heartbroken by missing out on a place in Spain's squad for Russia this summer.
He added: "I experienced it, it was a very hard moment that has already happened and it's not worth looking at the past. I'm going to do everything I can to go to the next one, it was a difficult moment because I thought I was going to go.
"When you start playing football and watch the World Cups on TV, it's your biggest dream to play it with your country, I had a very bad time, I wanted my team-mates to win it but of course I wanted to be there and it was a very difficult moment.
"There are times I have stopped valuing coming here, you do not think about it until you see the national team matches from your home and you know that it is the greatest thing to be with Spain, I hope to come for all the games."