Costa came off injured after scoring in the 3-3 draw with Everton on Saturday.Chelsea manager Guus Hiddink says Costa "was in a lot of pain. He will have a scan. We don't know the result. I hope it's not bad."
The potential injury will not jolt Chelsea into signing another striker in the January transfer window.
Hiddink says "for the moment, we are doing nothing (in the transfer market). We hope Diego comes out of the hospital in good health and we go on as we are doing."
Radamel Falcao remains unavailable with a "very serious" thigh injury, according to Hiddink. On loan from Monaco, he hasn't played since October.
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