The man who led the Red Army to Magners League glory in 2009 has been sidelined since March due to a troublesome groin infection.
O'Connell missed the closing stages of Munster's Magners League and Heineken Cup campaigns, as well as Ireland's summer tour of Australia and New Zealand.
And with the new season now just two weeks away, O'Connell is back in training but he admits he is not yet near a return to action.
"I'll be setting my sights around December, and anything else would be a bonus," O'Connell, who has been named as Munster captain again this season despite his injury, told The Irish Times.
"I went back running 10 days ago, and I've had no problems.
"I need to go about 12 weeks from when I stopped the antibiotics and get back into the heavy stuff, so I'm about eight-and-a-half weeks into that now.
"It's flying along at the moment. It was really slow at the start, but it's getting quicker now and going very well."
If O'Conell remains sidelined until December, he would miss the first nine rounds of the Magners League, with Munster's campaign beginning at home to Aironi Rugby on Saturday, September 4.
He would also be absent for the home ties with the Ospreys, Benetton Treviso and the Scarlets, as well as the trips to Edinburgh, Glasgow, Leinster, Ulster and the Dragons.
The 30-year-old would also miss the opening two games of European action and all four of Ireland's autumn internationals against South Africa, Samoa, New Zealand and Argentina.
His first game back could be Magners League clash with Cardiff Blues at Thomond Park on December 4, with the next two weekends taken up by rounds 3 and 4 of the Heineken Cup.
Guinness PRO12
Suite 208, Alexandra House,
The Sweepstakes
Ballsbridge, Dublin 4, Ireland