Wells played in City's defeat at Rotherham United last time out but missed the Capital One Cup triumph at Watford four days earlier due to a similar injury.
Parkinson has refused to completely rule out the striker for City's weekend trip to the Crown Ground but he admits it does look likely that the injury will need looking into further.
When asked about any injury issues currently within his squad, Parkinson said: "With Nahki, we have a problem with his hip.
"He is most probably going to have a scan on that (the hip) next week.
"I must admit that I have my concerns about it. He has training recently on it and looked ok, so it isn't completely stopping him.
"But there is clearly a problem there though, and we need to find out what it is."