"It's very frustrating," he told the Saints official website.
"I thought I was going to be able to train at the end of last week but it is still not right.
"Sometimes it is okay and I relax and forget about it and then suddenly I will get a jolt of pain.
"It might be something I just have to try and play through if it is not going to get any better, because I really do not want another operation.
"I am hoping the scan will discover the cause because after Euro 2004 I felt good and I was really hoping to get back on track this season.
"Now it looks as though I might be a few more weeks."