Bernard Brogan could be out for the season after sustaining a cruciate ligament injury in training.
The Herald report that the 33-year-old forward, who was named in the team to face Donegal on Saturday night but did not feature, has damaged his knee.
Jack McCaffrey was forced out of last September's All-Ireland final victory over Mayo with a cruciate injury but is hopeful of making it back for the Championship having had surgery back in in October.
The Dubs begin the defence of their Leinster title against the winners of Offaly and Wicklow on 27 May.
For Brogan, it could be an enormously disappointing end to a brilliant inter-county career.
He has five All-Ireland crowns and 11 Leinster titles to his name, and was named Footballer of the Year in 2010.