Northern Ireland, the Republic of Ireland and Scotland could have to wait until days before Euro 2020 starts next summer to seal their place in the finals if the coronavirus pandemic creates further problems with scheduling.
All three countries are due to be in play-off semi-final action next month, with the matches to decide the last four places at the delayed tournament set to be played in November.
However, European football's governing body announced the adoption of 'special measures' on Thursday designed to ensure the games go ahead amid the coronavirus pandemic.
It said that in the event of players being ordered to be quarantined or to self-isolate, matches would go ahead as planned provided there were at least 13 players available, including at least one goalkeeper.
However, if that was not possible, a UEFA document stated "the match will be rescheduled at a date to be fixed by the UEFA administration, including May-June 2021 preceding the start of the UEFA Euro 2020 final tournament".
The finals are due to begin on June 11 next year.
It added that the UEFA administration would retain the power to switch the match to a neutral venue if necessary, with the designated home team responsible for the staging costs. The semi-finals are all due to take place on Thursday, October 8.
Northern Ireland are away to Bosnia-Herzegovina, the Republic of Ireland will travel to Slovakia and Scotland are set to face Israel at Hampden Park.
The play-off finals are scheduled for Thursday, November 12.