The 28-year-old centre-back does not train with Premier League side Tottenham Hotspur between matches because of a chronic knee condition and so was a surprise inclusion in England manager Fabio Capello's 24-man squad.
King did not train with the England squad on Tuesday and a couple of hours after the session finished came confirmation of his return to Spurs in a statement issued by the FA.
"Ledley King has returned to Spurs Lodge to continue his rehabilitation over the course of the international break, following discussions and assessments overnight by the medical staff of both the club and the England national team," the statement said.
"It has been agreed by both parties that the best interests of the player are served by continuing his individual training programme at the club and he will play no further part in England's preparations or participate in the friendly against Slovakia or the World Cup qualifier against Ukraine."
Manchester City winger Shaun Wright-Phillips (back) and Portsmouth striker Peter Crouch (calf) also sat out Tuesday's session at Arsenal's London Colney training ground but neither of their injuries were considered serious.