Cattermole was shown the eighth red card of his career for a late off-the-ground tackle on his former Sunderland team-mate Ahmed Elmohamady in Hull's 1-0 win. He walked before ref Andre Marriner had even reached for his pocket.
Poyet said: "He didn't touch him. I thought it was a broken leg and he was going to hospital. He was down for two minutes.
"I like Lee how he is but of course it's dangerous for him because of his reputation.
"It was not his frustration. He's Lee Cattermole. If Lee Cattermole is a red, the challenge on Westwood is a red. McShane nearly cut his head off. And the scissor tackle on Johnson is a red. But they're not Lee Cattermole.
"I'm not happy. I'm complaining. I'm an honest person. If I thought Lee was a red card I would tell you. But it's not."
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