Derby winger Stephen Pearson has been ruled out for up to a month after scans revealed he had suffered a slight tear in his groin.
The 26-year-old had been an ever present this season before picking up the injury in training at the end of last week, forcing him to miss the 1-0 win over Bristol City.
The Scotland international had hoped to just miss the Robins clash but scans have revealed that he will face at least four weeks on the sidelines.
The winger is set to miss big games against the likes of Cardiff and Middlesbrough in the coming month as Nigel Clough's men bid to climb the table after ending their dismal run of four straight league defeats.
"It looks like Stephen will be out for four weeks," Clough said.