The dual Brownlow Medal winner had his return date for next season delayed after contracting a bacterial infection in his shoulder after going under the knife.
The initial diagnosis quickly cast great doubt over the midfielder's preparations for the new year, however new light on the 30-year-old's recovery timeline is sure to have given the Dockers a major boost.
"He's been able to start sweating after the infection got in there and we seem to be on top of that," Longmuir said.
"It's going to be a bit of a long slow process, in some ways it's disappointing.
"We expect him to be right and back in training by mid-Feb or maybe late Feb. We expect him to be right to go for the start of the season.
"All is not lost because he's been a pretty good bank of work under his belt so we expect him to come up to the mark pretty quick."
Fyfe played just the 15 matches in 2021 after dislocating his troubled shoulder in July, with the subsequent surgery causing further setbacks for the onballer.
The 22-year-old's exit leaves Longmuir with a sizeable void in his engine room, with Fyfe and fellow veteran David Mundy looking to lead a youthful midfield ensemble in 2022.
Rising stars Andrew Brayshaw and Caleb Serong are tipped for greater exposure in the centre next year, while the Dockers recruited Will Brodie from Gold Coast to aid their stocks.
Fremantle gained Pick 6 as part of the deal that sent Cerra to Ikon Park, with that selection and their own first-round selection of Pick 8 potentially being utilised to recruit a midfielder in Wednesday night's draft.