Gumbleton, 23, feared his career might be over after suffering back spasms last week, but coach James Hird said the surgery had revealed the reason for his chronic soreness.
Hird said scar tissue from an old operation had trapped a nerve in Gumbleton's back.
""He had a previous back operation, I think it was two years ago ... there was a lot of scarring around there and a bit of a problem to another disc,"" Hird said.
""It's a bit frustrating for Scotty, but if we had let it go and we had of gone like last year he would have had all those hamstring worries so in some ways it's a real positive.
""He's gone in, found out what the problem is and should hopefully be ready for the start of next year.
""He's gone in, found out what the problem is and should hopefully be ready for the start of next year.
""In some ways it's a big positive he had that back spasm last week as they've gone in to look at what's wrong.
""The surgeon was absolutely rapt with the way the surgery went. Scott should be back running around in six weeks.
""The surgeon has guaranteed him he'll have none of those hamstring issues next year,” Hird said.
Hird also ruled out selecting former Carlton and Brisbane Lions forward Brendan Fevola at next week's NAB AFL Draft.
""We've got Hurley, Hille, Ryder, Gumbleton, Carlisle, Crameri ... if there's one strength we have got it's key forwards,"" Hird said.
""We think we've got that position covered.
""If Brendan was a midfielder we might look at him.""
