Morata dropped out of Spain’s squad for the World Cup qualifiers against Albania and Israel after suffering the injury, which forced him to limp off in the first half of Chelsea’s 1-0 defeat to Manchester City on Saturday.
Morata underwent an MRI scan at a Madrid hospital, the RFEF revealed, in which it was confirmed he had suffered the grade two injury.
An injury of such magnitude could take up to eight weeks to recover from though the Spanish setup did not indicate a timescale for Morata.
News of the injury will come as a major blow to Morata, who Standard Sport revealed earlier today had hoped to recover in time for Chelsea’s first game after the international break, at Crystal Palace on October 14.
Chelsea boss Antonio Conte will face a selection headache in the absence of his top scorer, with Michy Batshuayi the only other senior striker available to him.
Though Batshuayi has scored five goals this season, including the winner at Atletico Madrid in last week’s Champions League tie, Conte notably did not turn to him when Morata came off injured on Saturday, instead bringing on attacking midfielder Willian to play alongside Eden Hazard.