Star Fremantle midfielder Nat Fyfe is understood to be under a significant injury cloud following the Dockers' Round 16 defeat to the Western Bulldogs on Saturday.

The 31-year-old Fyfe was substituted out of Saturday's clash at Marvel Stadium due to foot soreness in the same foot he battled a plantar fasciitis injury earlier in the year.

Since recovering from said injury, Fyfe played in eight straight games for Fremantle, including Saturday's contest.

However, the veteran star is now slated to miss a substantial period of time.

Speaking on SEN on Sunday,'s Josh Gabelich revealed the worry currently surrounding Fyfe.

"There's a great deal of concern [about] when we will see Nat Fyfe again this year," Gabelich said.

"He missed six weeks earlier in the year ... a bit of concern of if we see him again this year."

Dockers senior coach Justin Longmuir addressed Fyfe's ailment during Saturday's post-game press conference.

"His foot had gotten sore. It's the same foot he has had issues with this year," Longmuir said.

"It was sore and we had fresh legs (in substitute Neil Erasmus) so we thought we would get him in.

"It's too early to tell (if Fyfe will miss games). We will see how it pulls up."

Longmuir explained plantar fasciitis ailments can linger longer than anticipated.

"They never really go away until you have an extended period of time off," Longmuir continued.

"So he's had some awareness there, it just got a bit sorer than usual.

"He would be disappointed having been subbed out and it flaring up again but we will get him home and assess it further."

Fremantle is fixtured to host Carlton at Optus Stadium in Round 17.