Nothing at all. He was in a boot when he left after the game. The docs will have assessed him to decide if any bones were broken and I would have thought that if they were, he would have been taken straight to hospital. That he wasn't suggests that he has strained something. An Achilles accident is really easy to diagnose (if not the severity) and Dai would have said that. That suggests an ankle or heel injury. Either is very painful, but recovery can be quick. As it may be soft tissue damage, sometimes it will be left for a few days to calm down. It may not be for another week yet before we hear how good/bad it is. He seemed to twist and fall, so my guess is a twisted ankle.
Totally a guess, but that was all I saw when he went down.