Winger Kevan Hurst has suffered concussion after a blow to the head against Wycombe Wanderers on Saturday.
The Blues midfielder was replaced by Anthony Straker after 28 minutes in the 1-0 win after temporarily losing his sight in one eye.
And now the former Walsall wide man will be touch and go for Tuesday’s Johnstone’s Paint Trophy clash against AFC Wimbledon.
“Kevan took a knock to the head in the first half,” Blues physio Ben Clarkson told the official website.
“He lost his vision in one eye and then when he was substituted he got worse.
“Thankfully it was just as a result of concussion and we will have to see how he is for Tuesday now.”