Zeli Ismail is set to miss up to three months of action after undergoing surgery on a ruptured hamstring tendon.
The winger limped off in the 14th minute of City's Emirates FA Cup second-round meeting with Oldham Athletic last Saturday, and travelled to London for an operation yesterday (Saturday).
Ismail joined the club in the summer of 2019 and has made five appearances in claret and amber this season.
Bantams boss Stuart McCall said: “This is really unfortunate news - first and foremost for Zeli, but obviously for us a club, too.
“He has had terrible luck with injuries ever since joining Bradford City, and his setback sadly adds to our lengthy list of absentees.
“I know Zeli is devastated but will hopefully come back stronger. We all wish him the very best with his recovery and are behind him every step of the way.”