The inspirational Blues midfielder suffered a partial collapse of his lung during the 3-0 win against Coventry City last weekend and is rated as doubtful for the game against The Clarets at St Andrew's on Saturday.
"He was x-rayed on Monday, there were no broken ribs but he had a partial collapse of his lung so he is very, very sore," Blues boss Steve Bruce has said.
Bruce will however have top scorer Gary McSheffrey available again as he has now completed a three match ban for his sending off in the game against Derby County at St Andrews last month.
For a detailed head-to-head between the two sides, click here