"I was really happy to be here in the second half of the season," the 21-year-old told chelseafc.com. "Chelsea is my team and that was my dream, to be able to play for Chelsea. Obviously to go on loan is part of the journey but my target was always to come back here and play for Chelsea.
"They asked me if I was happy to come back and I said 'yes' straight away because to come back here to Chelsea was my target. My goal was to be able to be here, to train every day in the first team.
"I wasn't really expecting the call I was just doing my journey with Leicester and I was just trying to be focused on that and not think about other things. But when they called, I was really happy and really excited."
Casadei also said: "There are so many really good players that I knew that I would be able to learn a lot, even if I didn't get a lot of time in games. Still, training with them every day makes me improve, for sure.
"It was a great moment to play my first game for Chelsea, even though that was probably not the best game we played, when I made my Premier League debut against Liverpool.
"We lost 4-1 and I came on in a situation where we were already losing and it was difficult, but I still learned a lot and the atmosphere was amazing, because the chance to play in a stadium like Anfield doesn't happen every day. I was very happy."
On his loans away, Casadei added: "Football is more or less the same in all the world, but to go to another country and learn another language is difficult. I didn't know anyone here so it was not that easy, but going on loan helped me to grow as a player and as a person as well.
"In terms of football, I learned a lot because Reading and then Leicester were my first experiences in real football, between the adults. I had to be in a group of adults, not young guys. It helped me a lot because there is another tempo in the game, another intensity.
"That's why it is important to go on loan before you start playing for a team like Chelsea. You need experience in the way you play and train and everything else around it."