Dave Brammer could be out of action for the next three weeks after tearing cartilage in his knee.
Brammer picked up the injury in the win over Chester and an exploratory operation has discovered the damage.
The veteran midfielder has been dogged by injuries since joining Vale for a second spell.
But Brammer’s absence could be good news for loanee Adnam Ahmed who is seeking his first start for the club after joining on loan from Tranmere Rovers.
The Pakistan International seems to be the natural choice to fill Brammer’s position.