Sheffield Wednesday are reported to have paid more than £3 million for the former Watford midfielder last summer.
The Switzerland international has only played three times for the Owls this season, after an injury-hit debut campaign at Hillsborough.
Carvalhal revealed: “Almen has not trained since last week. We are analysing him to check how long he will be out.
“When you have a problem in the knee and try to protect the knee, sometimes you feel pain in a different part of the body. By trying to protect his left knee, he felt pain in his abductor on the right. It is something that sometimes happens. I hope soon he will be out of this.”
Abdi arrived at Wednesday highly recommended by fans of his former club, Watford. And the Owls will have surely done their own due diligence, having shelled out a reported fee of more than £3 million for the 30-year-old.
With 39 goals or assists in 131 games for Watford - for whom he played regularly in the Premier League until his return to the Championship, a year after winning promotion with the Hornets - Abdi's ability cannot be questioned.
However, his sketchy fitness record has got some Wednesday fans wondering if he'll ever play again - let alone for Carvalhal's side, with whom he is under contract until June 2019.
Here's what they are saying on Twitter:
Twatford proper saw the iceberg coming with Abdi didn't they. Clearly a great footballer but he's had more injuries than I've had KFCs #swfc— Robbie Jamieson (@robbiej2906) 14 September 2017
Abdi and Boyd two players who I thought would improve us, both out injured. Fear Abdi will retire quite soon, he can't stay fit #swfc— Rob Andrews (@Rob_Andrews95) 14 September 2017
Sheffield Wednesday fans - will the Owls' number 41 ever get back to his best?