Manchester United are amongst the clubs that were forced to delay ticket sales following a global tech outage.
Sky Sports News crashed on Friday morning after the major tech failure, with the outage sparking chaos across the world, while Sky News was also affected.
Hospitals, train services, banks, stock exchanges and TV channels were all knocked offline.
United had been planning to start selling tickets ahead of the new Premier League season, but sales were initially postponed until midday before later being rescheduled for 10am on Monday.