City’s Carabao Cup fourth round game at Southampton will now be played on Tuesday 20 December (7.45pm).
The tie was due to take place on Wednesday 21 December, but has been moved due to ambulance workers who are members of GMB, Unite and Unison going on strike meaning it could not take place on the original date.
Imps chief executive Liam Scully said: “This is a very frustrating situation for all involved and we understand the substantial disruption this will cause our supporters who are planning to travel to the game, and may have booked trains or accommodation. We share those feelings.
“But this is really out of the hands of both clubs and there was no one-size-fits-all solution - there is no other realistic date in the diary we could have moved the game to.
“For anyone who is now unable to attend please make sure you claim your refund, please let us know if you're struggling to get money back from a third party or change your plans via an email to firstname.lastname@example.org.
"And if anyone may be able to help our fans make alternate plans to attend please get in touch via the same email address."
All tickets for the match will remain valid, with spaces purchased on coaches also carried over.
Refunds for anyone unable to travel on the coaches must be requested by 10am on Friday 16 December, with ticket refunds available until 3.30pm on Monday 19 December - with physical tickets returned to the LNER Stadium ticket office.
City have already sold nearly 1,500 tickets, with fewer than 100 of the allocation remaining available. Should these not be sold out, they will come off sale at 3.30pm on Monday 19 December.