Jeff Hendrick will miss Derby County's "next few games" after suffering a tear in his thigh, but should be fit before the end of the season according to manager Darren Wassall.
The Republic of Ireland missed Derby''s 2-1 defeat to Cardiff City last weekend and is set for a number of weeks on the sidelines after a scan revealed that the thigh complaint was worse than first feared.
"We thought he had suffered a thigh strain but a scan has revealed a small tear," Wassall told the Burton Mail. "So, he will be missing for the next few games.
"We're in the hands of the medics. He's not going to be fit this week or next week but he will be back before the end of the season."
The news will come as a concern to Ireland boss Martin O'Neill, who is already sweating over the fitness of players such as Robbie Keane and Jonathan Walters ahead of Euro 2016.
Keane missed Ireland's friendly doubler-header with Switzerland and Slovakia, as did Walters, and both players had operations to correct niggling knee problems last week.
Hendrick also joins Shane Long, Kevin Doyle and Shay Given on the injury list as the European Championship draws nearer.