The plan was for Bell to have the operation when City were in a safe no mans land position in the Championship but with a calf injury adding to Bell's injury woes, City have opted to cut their losses and send the winger away for surgery.
"We are going to lose David Bell until the start of pre-season because he has had a bad reaction with his calf and knee," said Chris Coleman to the CT.
"He has been over-compensating for a problem with his right ankle, and his back is starting to play up as well.
"So rather than getting another couple of games out of him and risk causing more damage, we have had a chat and we are going to get him in as soon as possible to get some surgery done, which will, unfortunately, be the end of David for this season.
"We are not writing this season off but we know it is vital we have a good pre-season so we are cutting our losses with him and getting his surgery done."