Rotherham United captain Pablo Mills has been forced to see a specialist amid concerns that he has suffered a hernia that may require surgery.
The 24-year-old has missed the last two games after suffering a stomach strain in last month's FA Cup first round replay with Aldershot Town.
Meanwhile, Millers manager Mark Robins accepts that a heavy schedule of 12 games in 39 days since mid-October has taken its toll on his squad.
He told the Sheffield Star: "It had an effect but they were back in training on Monday and were buzzing.
"To be honest, I think myself and the staff have enjoyed the little break as well. Everybody seems refreshed and ready to go again."