https://www.sufc.co.uk/news/2017/august/season-cards/

The quality of the Blades off the field organisation is called into question again. Clear as mud.

What it seems to suggest is we've had problems with our computer system. We don't know which of the existing season ticket holders have been sent a new card or even if they should have been sent one. If you've got a new one sent to you we don't know why but use it anyway and destroy the old one. We don't know who else of the existing season ticket holders is being sent a new season ticket so if you don't receive one before the game hope for the best when you use your season ticket card this Saturday.

Perhaps someone going to the fans forum on Friday could get an explanation as to why this shambles has been allowed to happen and obtain assurances that there will not be any problems with season ticket holders gaining entry on Saturday due to system changes.