Harmes is contracted until the end of next year, having inked a five-year deal with the red and blue back in 2019.
The Melbourne midfielder was linked with Essendon at the end of last year, with the 27-year-old understood to have met with the Bombers in weighing up his future before a move failed to transpire, with Harmes pledging his allegiance to the Demons during the trade window.
The Devon Meadows junior has found minutes under Simon Goodwin harder to come by this season, having been utilised as the tactical sub on two occasions in his only pair of appearances following the opening two rounds.
Harmes didn't feature in the club's Round 9 win over Hawthorn and wouldn't play in the VFL either as Casey were scheduled for a bye. He spent some time away from the club earlier this year for personal reasons before returning to play through the VFL, where he averaged 32.3 possessions, 5.3 clearances and a goal per game from his trio of appearances.
A member of the club's 2021 premiership outfit, Harmes was also named as the medical sub at the back-end of last year before featuring in the club's finals run through September.
The situation surrounding Harmes has emerged as a "fascinating" one, according to 7 News reporter Mitch Cleary, who is of the belief Harmes could weigh up his future for the second time in as many years.
"He is a fascinating name. At the end of last year he was in and out of Melbourne's team. He was the sub in two of the last four games Melbourne played last year. He's 27 turning 28 in October," Cleary said on the Tradies Podcast.
"He's on a five-year deal that expires at the end of 2024. Now I'm putting him on the whiteboard as I think he is a genuine prospect to potentially move before that contract is up.
"Last year he had a look around because, as I said, he was in and out of the Melbourne team. He had a meeting or at least a conversation with Essendon's head of footy Josh Mahoney, who was formerly the head of footy at Melbourne and would have been there when they signed that initial five-year deal.
"Still right now he can't get a game. He's been in the sub a couple of times, he's had 35-40 touches in his last couple of VFL games.
"... So right now, the future is looking a little lean for James Harmes. Things have changed since he signed that five-year contract, which I don't he think was on massive money at the time.
"It gave him security, but it gave Melbourne a cheaper, still good money, option rather than have to sign him on two or three years bigger cash.
"... I think in the next 12 months something could move there."