Boss Aidy Boothroyd has selected Harrison for the first time ahead of fixtures with Scotland and Andorra, but the youngster - who has impressed in the MLS - has admitted that things did not go according to plan at the beginning of the week.
The 20-year-old is quoted by The Mirror as saying: "I missed the flight. I tried to contact someone at the FA but it was in the middle of the night.
"I decided to book the first flight out on Monday morning. I left New York at 8am on Monday and arrived here (St George's Park) at 10.30pm on Monday night. I'm still trying to figure the time difference out!
"It was $1,500 to fly to Heathrow. Then I hired a car service to get to St George's Park. I had to make it here!"
Harrison has been linked with a return to England, with Manchester City said to be leading Manchester United in the race for his signature.