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's 5-0 Group H qualifying victory over San Marino after a collision with goalkeeper Aldo Simoncini.
He seemed to be struggling to breathe normally and was accompanied to a hospital by the England team doctor Ian Beasley and kept in overnight for observation.
"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," the Football Association said in a statement.
The FA did not say exactly what the scan results showed.
Walcott had lengthy treatment on the pitch before being replaced by Aaron Lennon after the challenge, which angered England manager Roy Hodgson.
"If I described it as reckless I would be being kind," Hodgson said. "It was a very fierce challenge although I don't think for one minute there was any malice in it when he went for the ball. Irrespective of that it was a very bad challenge.
"When your goalkeeper does that you are very lucky to still have him on the field and not to have a penalty given against him. It did put a dampener on the evening."
The other good news for Hodgson was that Ukraine, which held England to a draw at Wembley last month, could only draw in Moldova, where England has already won 5-0.
"We go to Poland with a good strong squad with some players who will be quite fresh because they did not take the field," Hodgson said. "The one negative was Theo, that was a bad injury."
Hodgson, however, refused to call for San Marino, the joint-worst team in FIFA's world rankings, to be excluded from football's top tournaments.
Since becoming a member of FIFA in 1990, San Marino has won just once, against Liechtenstein in 2004.
"It's up to UEFA and FIFA to decide which countries they allow into their tournaments," he said. "San Marino have been in the Euros and World Cup for a good many years.
"I don't think we can accuse them of playing a dirty game of football, there weren't too many vicious fouls in the game, unfortunately there was one and that was the one that bothers us, but I wouldn't want to go as far as to say they shouldn't be allowed in the competition."
Information from Press Association was used in this report.