Last month, competition officials announced the decision saying it was a temporary move to make up for the lost 2020 season which was cancelled because of the COVID-19 pandemic.
But some clubs have suggested it will become a permanent switch.
“It will be good if it does only stay in place for next year,” LBU president Colin Bacon said.
“But if it the league elects to stay with an under 18s competition it won’t be doing our club any favours.
“No parent is going to want their kids stepping up from the under 14s to the 18s and playing against fully grown teenagers – it just doesn’t make any sense.
“A permanent change would mean we lose players and that wouldn’t be sustainable for us.
“Hopefully under 17s football does come back in 2022.”
Speaking to Australian Community Media, Colbinabbin’s Bernie Ryan and Elmore’s David Trewick held a similar view to their Cats counterpart.
“We are frustrated and in disbelief that the board would overrule an AFL recommendation to not reassess the change from under 17 to under 18 until 2022 without formal consultation with clubs,” Ryan said.
“As we have no under 14 (team), how do you think we will go telling a 13-year-old and his parents he is playing football against someone who has turned 18 post new year and drives to the football, drinks alcohol and can legally smoke?
“So what will that kid do? Not play football. So the league has opted to try and retain older footballers within our league, but still playing football, for the sake of young kids who will not be playing at all.
“We have talked to enough players and parents to realise we will find it extremely hard to field a side next year.”
Trewick added: "We've always been strong supporters of the under 17s. The under 18 age bracket is a bit big for some of the under 14 kids we have playing.”
“We've always enjoyed the under 17 environment. Due to the current situation and with the playing list we've got, for one year it might fit the agenda of Elmore, but I'd like to see it revert back to under 17s the following year.”
HDFNL chairman Peter Cole said the decision was made to help protect clubs from losing players to rival competitions.
“From the figures we've already been given by some of our clubs, it's in excess of 80 players who would have been ineligible to play under 17s next year,” he told ACM.
“While some of those players would have played reserves and seniors, the majority most likely would have gone elsewhere or simply not played and that's unacceptable in the current climate.
“By moving to under 18 for next year - and at this stage the move is only for 2021 - what we're giving the clubs is the opportunity to be able to retain those players.
“What it essentially means is the existing teams that clubs had ready to go for this year can still be retained for next season.
“We acknowledge the under 17 vs under 18 subject has been regularly debated within our competition over the years, but in this instance it's purely about giving our clubs the maximum opportunity to field sides.
“We'll see how next year goes with the under 18s and then review it at the end of the season.”
More sport news
HDFNL clubs not shocked by salary cap cuts
Good things come in three for Colbinabbin
Steve Stroobants to lead Rochester charge again
15°C