The 25-year-old, who joined the Blues from Real Madrid last year, enjoyed a flying start to life at Stamford Bridge, but could not build on it and found himself out of the side.
He scored just three times in 23 games in the second half of the season and missed out on Spain’s World Cup squad as a result.
And Morata, who has earned a recall for his country’s UEFA Nations League games against England and Croatia, thought about leaving the Premier League club in favour of a return home or a move 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.
“Not going to the World Cup was hard for me. I did not have the best season and the coach made the decision.
“I signed for Chelsea to be there 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 won 23 caps, admitted he took his international career for granted and was left heartbroken by missing out in 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.”
Rice was omitted from the Republic squad for Thursday’s UEFA Nations League opener against Wales in Cardiff with manager Martin O’Neill revealing the West Ham defender is still deliberating over switching loyalties to England.
London-born Rice has three senior caps for the Republic but they all came in friendly matches, meaning the 19-year-old could yet decide to represent England instead.
Warrington-born Brooks, like Rice, has appeared in three international friendlies, but the Bournemouth forward is set to end any doubts over his future by representing Wales in a competitive fixture against the Republic, who the Welsh face in Cardiff on Thursday.
“There is a decision to be made by younger players like Declan Rice and myself,” said 21-year-old Brooks.
“I don’t know his situation and what he wants to do so I can’t really comment on that. But for me it was always going to be Wales and thankfully I got that opportunity.
“I won’t be switching even if I don’t get on against the Republic.”
Brooks did represent England Under-20s at the Toulon Tournament in 2017 when he was named the competition’s best player.
But Brooks, whose mother Cathryn is from Llangollen, joined the Wales set-up after that tournament and has won senior caps in friendlies against France, Panama and Mexico in the past 12 months.
“You obviously listen to what your family have to say and there’s other influences involved as well,” Brooks said of his decision to play for Wales.
“You can get all the advice in the world, but if you want to do something for yourself you have to (make a decision).
“There’s no going back from that and I can’t wait to get the Wales shirt on again.”
Brooks’ previous international experience came when he was a Sheffield United player.
But an £11.5million switch to Bournemouth has turned him into a Premier League player and he feels he is already benefiting from his summer move.
“Eddie Howe (the Bournemouth manager) has been great to work with,” Brooks said.
“The training has been spot on and I can see myself improving already, and hopefully it can continue.
“It’s the same with Wales as the quality in our squad is there for all to see.
“I’m a big Manchester United fan and I grew up watching the gaffer (Ryan Giggs).
“He was a fantastic player and won near enough every trophy under the sun, so I’m delighted to work with him.
“It was a bit strange meeting him at first, but I’m used to it now and I’ve just got to kick on and try and impress him.”
Raheem Sterling has withdrawn from the England squad for the internationals with Spain and Switzerland due to injury.
Manchester City forward Sterling has suffered a back problem, according to a statement from the Football Association.
Gareth Southgate’s Three Lions host Spain in the UEFA Nations League at Wembley on Saturday, before taking on the Swiss in a friendly at Leicester’s King Power Stadium three days later.
Manager Southgate, who celebrated his 48th birthday on Monday, does not plan to call up a replacement.
The remaining 21 players in the squad are due to train for the first time on Tuesday morning at St. George’s Park.
Sterling has scored twice in three Premier League appearances for City so far this season, including the opener in Saturday’s victory over Newcastle.
The 23-year-old has won 44 caps for his country, scoring twice, and made six appearances at the World Cup in the summer as England reached the semi-finals.