Monaghan's All Star forward Conor McManus is facing up to ten weeks out of the game with ankle ligament damage.
McManus damaged ligaments playing for club side Clontibret just days after Monaghan's Allianz League Division 2 final victory over Donegal.
The Farney County will play Down or Tyrone in their Ulster Football Championship opener on 15 June.
McManus is currently wearing a protective boot and attending the Santry Sports Clinic, as well as working with four-time All-Ireland winning coach and herbalist Sean Boylan on alleviating the injury.
The specialists will give the injury another week to heal before deciding whether surgery is necessary. If it is, the corner-forward will face ten weeks on the sidelines.
Speaking to the Irish Independent about the injury, McManus said: "There's nothing I can do at the moment, but just wait.
"I hurt my knee also, but thankfully that is only lateral ligament damage, but the ankle is a lot worse and it's going to be another week before I know what will happen.
"If there's an operation, you are talking probably eight to ten weeks, but I'd be hoping for good news.
"I have to prepare for the best-case scenario, so at the minute I am just remaining positive."