Donegal have pulled out of Sunday's McKenna Cup semi-final with Monaghan.
They've cited player unavailability and player welfare concerns for withdrawing.
Following last night's win over Derry, Donegal manager Declan Bonner said he wouldn't be able to field a side due to some players' Sigerson Cup duties.
Ulster GAA say the counties turned down the opportunity of bringing the McKenna Cup forward to avoid such clashes.
Bonner told Highland Radio, "regrettably we will not be fulfilling this fixture".
Down's semi-final with Tyrone is set to go ahead as planned at the Athletic Grounds in Omagh.
Following a meeting of the Ulster CCC they said, "the committee also considered the welfare of players and took the view that from a player perspective, it would be unfair to expect players to play in the Sigerson Cup on Sunday 12th and line out for their counties on Tuesday 14th - and potentially be expected to play again for their county in the Bank of Ireland Dr McKenna Cup Final on Saturday 18th January (and perhaps for their University the following day).
In response to a request from Off The Ball, the GPA gave the following statement on the matter:
Our position would always be that player welfare has to come first.
Players shouldn’t be expected to ‘double up’ on games or be expected to make a choice between one over another.
A more coordinated fixture calendar is required and that’s what we are working towards with the fixtures review task force, on which we have a representative, to ensure situations like these do not arise going forward.
Donegal could now face sanctions or a fine as a result of their actions.