Anthony Gardner is facing a lengthy spell on the sidelines after scans confirmed a tear of the Achilles tendon.
The Owls’ skipper suffered the injury during the 1-1 draw with Middlesbrough last Saturday at The Riverside Stadium.
Manager Dave Jones said: “Anthony will see a specialist in London and have an operation on the Achilles.
“It’s a blow to the boy and the team because he was playing very well and had a good start to the season.
“We wish him all the very best in his recovery and look forward to welcoming him back as soon as possible.”