Nathaniel Mendez-Laing, the Bluebirds winger injured at Huddersfield, could be out for six months.
That is a major blow for the player and Cardiff City after scans showed the damage sustained in a collision with Huddersfield’s goalkeeper.
Mendez-Laing is in a leg brace and has damaged ligaments in his left knee. He will be out for between three and six months.
Junior Hoilett and Aaron Gunnarsson are likely to be ruled out of Tuesday’s Carabao Cup tie against Norwich City by injuries, although manager Neil Warnock is expected to make changes to his starting line-up.
Alex Smithies will make his Cardiff debut in goal with Greg Cunningham, Lee Peltier, Matthew Connolly and Jazz Richards likely to make up the back four.
Loic Damour is in line to play his first minutes of the season and Callum Paterson looks likely to start, although he played most of the 90 minutes at Huddersfield after Hoilett was injured.
Kadeem Harris, Bobby Reid, Danny Ward and Gary Madine and all in contention.
Neil Warnock selected his Cardiff City side to face Norwich City in the Carabao Cup before the Bluebirds’ Premier League clash with Huddersfield Town.
“I picked the team to play against Norwich last Friday,” said Warnock.
“When I put it up on the board I thought ‘bloody hell!’.
“When I came to the club I’d have settled for that team in the Championship. It’s not bad a squad we’ve got. We’ve done that over 18 months.
“Everybody who didn’t play at Huddersfield will get a chance. And then we’ll have to fill in with one or two that have been in the squad to make up the numbers.
“It’s a good game for us. I need to look at one or two things and that’ll be a good opportunity for me.”
Canaries boss Daniel Farke is also weighing up wholesale changes and is expected to make up to eight changes.
Norwich go into the game following a 3-0 defeat against Leeds United and Farke says: “It won’t be easy at Cardiff because we are playing an away game in the cup against Premier League opposition.
“But we will try to recover pretty quickly and be there with a strong squad in order to try to go into the third round.”
European qualifiers Manchester City, Liverpool, Manchester City, Manchester United, Tottenham, Liverpool, Chelsea, Arsenal and Burnley go into the draw at the third round stage.
Who plays who in the last 32 will be decided at the Sky Sports Studios, London on Thursday (7pm).
Cardiff City (4-4-2), possible: Smithies; Richards, Peltier, Connolly, Cunningham; Damour, Paterson; Reid, Harris; Ward, Madine.
