The Olympic heptathlon champion pulled out of the Great Britain squad bound for Russia after the injury resulted in a below-par performance in the Sainsbury's Anniversary Games in July.
Ennis-Hill, who today unveiled a floating sculpture of a swimmer on The Serpentine in Hyde Park to celebrate the upcoming PruHealth World Triathlon Grand Final, is undergoing rehabilitation and hopes to be back in action by February.
"The rehab's going well and I'm just building back into training. I think I'm on course, it's just taking a little bit of time after backing off training and allowing it to heal," she told Press Association Sport.
"I'm having to take it as it comes at the moment, but my plan is to come back for the indoor season next year. I hope to do an indoor season."
The Anniversary Games was only Ennis-Hill's second competitive appearance since winning gold at London 2012 after sitting out five meetings between May and July.
Mindful of the potential long-term consequences of rushing her rehabilitation, the 27-year-old is determined to prevent the Achilles from becoming a recurring problem by ensuring she makes a full recovery now.
"I can't run just yet, but I'm doing bike and pool sessions to get my fitness back and get on top of this Achilles injury so it's not an issue next year," she said.
"Now it's a lot better in terms of pain. I was having pain when I was training and running and it was stiff and sore in the morning, but that's settled down now so I can keep pushing on.
"I have the time now so I can make sure that I do things properly. My medical team are very aware that sometimes you can push it a little bit too much when you have an Achilles injury.
"That can leave you with a problem for years, so it's about being sensible and making sure I get on top of it now so it doesn't cause any issues in the future."
Ennis-Hill insists withdrawing from the World Championship, a competition in which she won gold in 2009 and silver in 2011, was the correct call.
"I really wanted to be there and in the weeks leading into it I thought I'd be there, but then I'd have a setback. Then I'd be OK again and then I'd have another setback," she said.
"It was really difficult to get to the point where I needed to be, but I know now it was the right decision.
"I needed to make sure that I can get it 100 per cent right so that I can carry on competing for a few more years.
"It's always difficult to watch when you're injured because I wanted to be there.
"But there were some amazing performances - Mo Farah won again and Christine Ohuruogu did well. I was proud of my team-mates."
Alistair and Jonathan Brownlee, winners of the gold and bronze medals at London 2012, will battle it out to become ITU World Triathlon Series Champion in Hyde Park on Sunday.
"I know the Brownlees, I see them in Leeds. I've never done a triathlon before and I don't think I'd be very good," said Ennis," a PruHealth Vitality ambassador.
"I can swim, run and cycle but don't know if I could put them all together back to back. It's a difficult event, but I like to support all multi-discipline sports."