The 31-year-old former Swansea and Gillingham striker has been on the sidelines for the last five and a half months but appeared to be progressing well when he scored for the reserves in a 2-1 win over Burton.
However, the Malian was injured during training on Thursday morning, although the club have not confirmed the nature of the problem.
But defender Ryan Shotton posted on his Twitter page: "Mama I can't have enough sympathy for you son, much love," before going on to add, "it is his Achilles again yeah, not a good day for all of us."
A Stoke spokesman said: "Mamady did pick up an injury and finished training early. We are awaiting scans to discover the extent of the injury. We do not want to speculate until we have the results of those."
Source: PA
Source: PA