Kamara has only just returned from a serious knee injury and Cash says the midfielder has been missed.
"He has so much ability - natural ability - and he’s worked really hard to get back during the time when he’s been injured," Cash admitted. "Then he had a little hamstring. He’s not really trained. How well he played against Juventus when he’s not really trained, I think he’s brilliant.
"It’s the simplicity of his game, he keeps the ball and his interceptions are unbelievable. He manages to get his body in the way and then finds a pass. Yeah, he’s a key player for us when he’s fit."
Asked how much Kamara has been missed, Cash said: "A lot. He’s a key player for us. When he was fit, he was a difference maker. He’s a very underrated player.
"I think people talk about a lot of our players - but he’s not one of them that is spoken about. I’ve said that before. He’s a big asset and he’s underrated. So it’s good to have him back and playing like he is."
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