Alvaro Morata joined Chelsea against the wishes of Zinedine Zidane as he did not want to spend another season among the Real Madrid substitutes.
The Spain international signed for the Premier League champions in July for a reported club-record fee of £58million, despite having only returned to Madrid the year before.
Morata made 43 appearances in all competitions last season but only 19 of those came as a starter, with Karim Benzema preferred as first choice.
The 24-year-old says his desire to "grow up" and force his way into the Spain starting line-up for next year's World Cup prompted his decision to turn his back on Madrid for the second time in his career.
‘I’ve only scored and assisted with my head for Chelsea, so I hope to use my feet as well soon!’ - @AlvaroMorata
— Chelsea FC (@ChelseaFC) September 14, 2017
https://t.co/oayFTPyLJI pic.twitter.com/XtdjnbzzDB
"Zidane wanted me to stay and I was happy in Madrid. But I couldn't stay to be a substitute," Morata, who joined Juventus in 2015 on a permanent deal, told the Daily Mail.
"You reach a point that you need to play, to grow up, to escape a comfort zone. It's about being comfortable. I don't want that. I am ambitious and hungry to succeed.
"For Spain, the more I play, the more goals I score, the more chance I have of making the World Cup and starting games."
9 – Only Andrea Belotti (10) has scored more headed league goals in Europe’s big 5 divisions since Aug 2016 than Alvaro Morata (9). Bonce. pic.twitter.com/1HqrIwlH78
— OptaJoe (@OptaJoe) September 9, 2017
Morata has enjoyed a strong start to life in England, scoring three goals in four league appearances, and he has explained how training with the elite at Madrid and Juve has helped him to acclimatise quickly.
"If I score every game with my head, no problem. I don't care if it's a bobble off my knee or it goes in off my a***, a goal is a goal!" he said.
"At Real Madrid, I did heading drills with Cristiano Ronaldo. You see him go up for headers, that spring and power, he is a real beast. At Juventus, I saw Fernando Llorente, how he finds space and directs his headers.
"I like the physical challenge. Last week, I played against Wes Morgan and Harry Maguire – big guys. Cesc Fabregas was putting in good corners that I thought I could get to and bury but there were some coming in and I couldn’t even get a jump up against those guys.
"But then I got between them to score. You have to be clever. I'm not worried. At Juve, I trained against Giorgio Chiellini and Leonardo Bonucci every day.
"I think the Italians saw this handsome kid coming from Madrid, where it is a bit softer, and it was a good education. They were great mentors."