Dawson was carried off the pitch at Karachi’s National Stadium after pulling up during a fielding drill in England’s training session on Saturday night and returned to the team hotel in a wheelchair later that evening.
“After being assessed in Karachi, he will be unable to continue during this tour of Pakistan and will fly home to the UK on Wednesday,” the ECB said in a statement.
Dawson was one of Matthew Mott’s three assistant coaches for this tour along with Carl Hopkinson and David Saker, with Michael Hussey due to join the staff ahead of the World Cup in Australia.
The ECB said that a replacement coach for the World Cup would be “announced at a later stage”.
England have separated coaching staff between Test and white-ball cricket since Rob Key’s appointment as managing director earlier this year but Dawson’s injury may require one of Brendon McCullum’s assistants to be drafted in.