Rotherham United have decided that right-back Mark Lynch needs an exploratory operation on his injured shoulder.
The 27-year-old summer signing from Yeovil Town suffered the problem in the closing stages of last month's 1-0 victory against Luton Town and may need corrective surgery.
"We want to ensure we do what's right," said Millers boss Mark Robins. "Mark had a good start with us and this injury was a blow for him."
The former Manchester United trainee had scored twice in nine appearances for the club before picking up the injury.