The Cameroon international suffered the knock 39 minutes into Saturday's 1-1 draw at Loftus Road and was stretchered off.
Mbia was unable to confirm exactly when he will be back in action but the 26-year-old has allayed fears over the seriousness of the injury.
The defensive midfielder told his official Twitter account: "Nothing serious, it was a small neck issue, nothing serious, i will be back very soon."
He added: "I am in the hospital. I will be back when I can. I can't tell you exactly when I can."