Millwall right-back Jason McCarthy is set to be on the sidelines for six-weeks after sustaining a serious toe injury. 

McCarthy, 24, signed for Millwall in the summer from Wycombe Wanderers for an undisclosed fee to provide competition for Mahlon Romeo. 

The defender posted a picture on Instagram of him in a protective boot during the week as he celebrated his birthday with his family. 

Millwall manager Gary Rowett explained the extent of his injury after the Lions 2-1 victory over south London rivals Charlton. 

"He has split the cartilage in his toe so because it is an awkward position it probably looks like he is going to be out for maybe about six weeks," he said. 

 "It is a disappointment but yeah that is what happens."

McCarthy's injury means Mahlon Romeo is the only registered fit first-team right-back in the squad as James Brown is still recovering from an ACL injury and Danny McNamara was loaned out to Newport County in the summer.