It is understood that three players – Mark McHugh, Gary McFadden and Thomas McKinley – have withdrawn from the Donegal senior football panel.
McHugh, an All-Ireland winner in 2012, was used as a substitute on Sunday last when Donegal lost out to Monaghan in the Allianz National Football League Division Two final. He was introduced before half-time.
He was not at training with Donegal on Tuesday night, thus triggering speculation that he has taken his leave of Jim McGuinness's squad.
Son of 1992 All-Ireland winning hero Martin McHugh and brother of current county panellist Ryan, Mark has played a significant role in Donegal's progress since McGuinness took command.
He was unable to start Donegal's last league game against Armagh because of injury which may have militated against his prospects of starting against Monaghan at the weekend.
Gary McFadden and McKinley have been peripheral members of the panel but both have been prominent of late for their respective clubs.
Meanwhile, Cavan manager Terry Hyland has thrown down a challenge to his squad to prove they are worthy of selection for the Ulster Championship quarter-final against Armagh.
The Breffni county shipped two demoralising setbacks within a week with the loss to Dublin in the All-Ireland U21 semi-final and the defeat to Roscommon in the Allianz League Division Three final.
"We have to recognise that it is a big step-up from Under-21 to senior level and there are those who are unable to take that step," points out Hyland.
But it's over the forthcoming championship that he believes his players can show their mettle.
"There is no point in us having good lads around us if we don't give them the chance to show what they can," stresses Hyland.
"The league was very beneficial in that respect but now they must step up to the next level."