After Michael Carrick left the squad with a groin injury on Wednesday, Roy Hodgson's options have been depleted further with the loss of Townsend.
According to a statement from the Football Association, the 23-year-old "reported for duty on Monday with a minor injury and will go back to Tottenham Hotspur for further treatment".
Townsend, who has six caps, will miss the European Championship Group E qualifier against Slovenia at Wembley on Saturday, and next week's friendly with Scotland.
The midfielder has struggled to find the form that saw him earn his first England cap last season, as struggles with injury have seen him make just five Premier League appearances so far in 2014-15.
He scored one of England's five goals against San Marino in October, but has been an unused substitute in the other two qualifying matches.
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