O'Driscoll said: "He's on crutches and it looks like an Achilles injury. We won't know how serious it is for 24 hours or so until things settle down.
"It was a clumsy tackle from Kitson. I don't think it was anything malicious but it was clumsy."
Reading boss Steve Coppell defended Kitson and insisted the striker had not tried to hurt Coppinger.
"I don't think anyone could say it was a dirty or malicious challenge," he said. "It was just an innocuous challenge in the middle of the park. Nothing more, nothing less."