The Greek Superleague game between leaders PAOK Salonika and Olympiacos was abandoned on Sunday before a ball was kicked after Olympiacos coach Oscar Garcia was hit by an object thrown from the crowd.
The former Watford boss was struck in the face, reportedly by a toilet roll, and the teams left the field as he received medical attention before being taken to hospital.
Olympiacos wrote on their website: “The coach of our team was hit by an object that was thrown out of PAOK’s fans and our team left for the locker room.
“Mr Garcia left Toumba for a hospital in Thessaloniki so that he could take the necessary examinations.”
PAOK lead the standings by two points from AEK Athens, with Olympiacos a further four points back in third.