The 28-year-old picked up the injury in the second half against the Belgians and he had to be carried off on a stretcher before being replaced by Chelsea defender Emerson Palmieri after 79 minutes.
Sky Sport Italia reports that the Italy medical staff have confirmed that Spinazzola had suffered an Achilles tendon injury in his left leg, and an injury such as this could result in 12 months out of action. Further tests will be conducted by the Azzurri medical staff before an official diagnosis is made.
This is a major blow for coach Roberto Mancini and the Azzurri squad as the Roma defender had been one of the stars of the tournament up to this point and he earned the Star of the Match awards for his performances in the victories against Turkey and Austria.
Emerson Palmieri will likely start in place of Spinazzola for Italy in their semi-final against Spain on Tuesday evening.