The free-scoring Notts batsman has been called up to the England team as he completes his four-year qualification period in October and said it was 'a dream come true'.
He added: "I've been told I'm in the side to do Freddie's job and they are big shoes to fill.
"But I'm certainly up for the challenge and can't wait to pull on the England shirt.
"I'm delighted and thrilled to bits. I don't think it has really hit me yet and it will take time to sink in."
The 24-year-old will spend a month training at the England Academy training joining up with the squad along with Matt Prior from Sussex, who spent last winter at Loughborough with Pietersen.
"I know Matt well from last winter and it's nice to have a few familiar faces in the squad with me.
"To play for England has been my goal since arriving from South Africa and now I want to produce the performances to keep me in the side.
"I'm enjoying a short holiday at the moment but I'll come back refreshed and totally focused on showing I've got what it takes at international level."
THURSDAY 21 SEPTEMBER 2017
ENGLAND v WEST INDIES