The Football Association have confirmed that Ledley King suffered a groin muscle strain in the first half of England's 1-1 draw with the USA on Saturday evening.
They have also revealed that the Tottenham defender will be monitored on a daily basis amid reports that the player's World Cup was over.
King did not take part in training on Monday and has already been ruled out of Friday's Group C game against Algeria.
Wayne Rooney also failed to take part in the session because of an ankle knock while left-back Ashley Cole was another absentee.
Rooney's injury is not thought to be serious, while Cole has been missing full training after games to aid his recovery from the broken ankle he suffered in February.
King was replaced by Jamie Carragher in Saturday's match but the Liverpool man struggled so Fabio Capello could bring in Matthew Upson or Michael Dawson to partner John Terry in the heart of defence against Algeria.
Rio Ferdinand was ruled out of the World Cup after suffering a knee injury in training.