Theo Walcott will play no part in Tuesday's World Cup qualifier against Poland after being ruled out with a chest injury.
Walcott was injured in the opening minutes of Friday night's 5-0 win over San Marino after a collision with goalkeeper Aldo Simoncini.
He seemed to be struggling to breathe normally and was accompanied to hospital by the England team doctor Ian Beasley and kept in overnight for observation.
"Theo Walcott has been ruled out of the FIFA World Cup qualifier with Poland on Tuesday with a chest injury," the Football Association said in a statement.
"The Arsenal forward was taken to hospital following a collision with the San Marino goalkeeper on Friday night. He was monitored overnight as a precaution and, following scan results today, will return to his club for further treatment."
While no exact diagnosis has been revealed, Walcott looked in trouble immediately after the incident, which left manager Roy Hodgson very unhappy.