The autopsy on Italian footballer Piermario Morosini has proved inconclusive.
The 25-year-old former Italy Under-21s international midfielder died on Saturday afternoon after suffering a cardiac arrest while playing for Livorno against Pescara.
A six-hour post-mortem examination was carried out on Monday but no cause of death was determined.
Coroner Cristian D'Ovidio told La Gazzetta dello Sport: "There is no macroscopic evidence that allows us to determine his death.
"Further tests are needed, even of toxicological nature."
All Serie A games were postponed following Morosini's death, but new dates have now been published.
