Tomkins knows he will be a central figure, first at Old Trafford on July 26 when Great Britain open their campaign against Senegal, and then at Wembley three days later when Group A outsiders UAE are the visitors.
"I never expected it," said the 23-year-old. "All the years since we knew it was coming to London, you never once thought you'd be taking part in it.
"I've seen so much building work going on over the years. I've been travelling past it everyday.
"It's going to be incredible for the whole country. We can't wait for it to begin."