FREMANTLE expects Brownlow medallist Nat Fyfe to resume running when the club returns to training on January 4 despite injuring his back at training.

However, respected sports medico Dr Peter Larkins says the bulging disc could flare up during the season with an awkward tackle or over-stretching in a marking contest. 

Fyfe injured his back during the Dockers' final pre-Christmas session on December 21.

Seven News in Perth reported the superstar would miss up to two months with the injury, but Fremantle told AFL.com.au on Monday that was incorrect.

Scans on his back revealed no need for surgery but there's no guarantee Fyfe will be fit to take part in the club's first 2016 NAB Challenge game against Richmond.

Dr Larkins told radio station 3AW that Fyfe could be back to full fitness in three weeks but there was a real risk of the injury reoccurring.

"Landing the wrong way or the wrong sort of tackle can compress the back again and of course a little more disc bulges out, so he will be prone for the rest of his life, literally, to getting a further incident if things go wrong," he said on Monday evening.

"But it can settle down completely and not restrict him on running or bending, and it can settle down within 3-4 weeks in a lot of people if they do the right things."

While conceding there was no good time to suffer a back injury, Dr Larkins said the timing of Fyfe's complaint was about as good as possible. 

"It's an unwelcome interruption but if you're going to have it, this Christmas-New Year time is the time to have it because players are backed off a little bit," he said.

"It wouldn't be something you'd want to do in February when you're getting ready for matches. Hopefully he'll be right to go."

Fremantle kicks off its pre-season campaign against the Tigers in Mandurah on February 19, before facing Adelaide (February 28) and Geelong (March 12).

Fyfe suffered a number of injuries in the latter part of the 2015 season but was still able to clinch a first Brownlow Medal for the Dockers, and indeed played with a broken leg during the club's preliminary final loss to Hawthorn.

The 24-year-old averaged 29 disposals a game this season and led the league for average contested possessions and clearances.