Barkley joined Chelsea from Everton in the summer and is slowly becoming a valuable member of Sarri's side.
Despite his recent improvemnet, 24-year-old spoke about his furstrating year.
"It’s been a frustrating few years for me, but I believe you just have to work hard and good things will come to you down the line.
"The first thing I want to say, is that I’m over the moon to be back with England.
"It’s been a while since I’ve been called up and this is the first time I’ve been selected since I’ve been with Chelsea", Barkley said.
Despite missing out on the World Cup, the attacking midfileder has hopes of one day representing England at a World Cup.
"Thinking back to the summer and the World Cup, of course I would’ve preferred to have been in Russia with the lads, but sometimes you just have to accept where you’re at.
"I’m still only 24 though, so hopefully I have a lot of years ahead of me and I can be involved for all of them", he added.
Barkley moved to Stamforf Bridge for £15m in August, and the former Sheffield Wednesday loanee is happy with his decision.
"On a personal level, I’m really enjoying my time with Chelsea. It was a big change for me, moving down to London because I’m a Liverpool lad through and through.
"It’s all helped me mature as a person and a player too. I moved down to London on my own and I live just off the King’s Road, so I can even walk to Stamford Bridge, which I used to do last season before we stay overnight for the games at the moment", he added.