Last year's grand finalists have their backs against the wall after the loss of Mitch Haddrill, Jeromy Lucas and Matt Wallis for the upcoming season.

Haddrill, a two-time Gerald Clear Medallist, has retired for the second time, while Wallis, the league's leading goalkicker this year, has moved to Melbourne.

Lucas, who claimed the club's best and fairest and finished third in the Gerald Clear Medal, remains based in Melbourne but will be unable to travel back due to university commitments.

This comes on top of the loss of Lenny Haddrill, who has decided to remain in Canberra, and Tom Alexander to Lockhart.

Harper conceded the challenge was now in front of the Jets.

"Absolutely. It is going to be a massive challenge for us," Harper said.

"We were able to cover the losses of Lenny and Tommy A with the recruits we were able to bring it, similar style of players and what not but the big losses of Matt Wallis, Haddrill and Jerry Lucas, it does make it a bit more challenging.

"I think our new forward dynamic is going to be one that is really hard to defend for opposition teams and I'm really confident with how that's shaping up at the moment.

"We're just full of young blokes that are probably eager to start making a name for themselves now and take on some responsibility.

"I've got full faith in what we're going to achieve this year, it's just a matter of putting all the pieces together and blokes taking that responsibility on and go 'you know what it's my time to really be in it and show my colours here'."

The return of Haddrill, from a one-year retirement, and Lucas to the Jets last year inspired their rise from outside the top five to grand finalists, where they were beaten by seven points by The Rock-Yerong Creek.

Wallis missed the grand final with a dislocated elbow that he sustained in the first semi-final and was considering having the year off anyhow.

Harper paid tribute to Wallis' contribution to the Jets, where he kicked 232 goals over four seasons.

"It's a massive loss to lose Wal. He's been arguably one of the better key forwards going around this way for a while," Harper said.

"He's won multiple goal kicking awards, consistently delivers, has done for us and previously Temora.

"It's definitely a loss for us up forward but off the field as well, he was quite good with sponsorship stuff and tasks that needed to be done. He's going to be a big loss.

"Hopefully we can fill that hole. We're going to do a couple of positional changes and a couple of structured moves so things are shaping up nicely even though he has moved on."

Harper explained that Haddrill and Lucas both don't have the time to commit to another season.

"Mitch, he's had his third kid now and it's just getting a little bit too much," Harper said.

"His body copped a fair bit of a flogging last year and I think he just needs to have some more time off.

"Whether or not he comes back after it or not I'm not really sure but at this stage he's retired again. It's not ideal for us but we've got to respect it nonetheless.

"Jerry's in Melbourne. He's a no at the moment and at this stage may not even be playing footy. I just know he won't be with us."

On top of that, Lachie Jones, ruck in the Farrer League Team of the Year in 2023, will miss the start of the season due to an overseas trip.

"Lachie will have a delayed start to the year at this stage," Harper said.

"He's going to America for the first couple of rounds at least and he's got a couple of other things clashing at the minute."

The upside is that they have welcomed back Rhyle Davis from Collingullie-Wagga, to go on top of the prior recruitment of Charlie McCormack, Max Harper, Paddy Bray and Harry Collis.

"Rhyle is a Jets junior. He can be an outside mid or half-back," he said.

"He's fitted in really well, he's training the house down, he's fit and looking to solidify his spot in first grade here and prove a point too I think."

Not only does Davis have a point to prove but Harper says that's the way the Jets will be attacking the season.

"I guess we might snag a bit of an underdog tag at stages throughout the year and that might even play into our hands to be honest with you," Harper said.

"I don't mind an underdog tag, a lot of our guys being local guys and farmers out here often get forgotten about and maybe disregarded at stages and a lot of these blokes at times take it to heart that these Wagga teams try to run all over us and run the show and what not.

"I feel like this year we'll be playing with a bit of vengeance and we'll give it a red hot crack again."

The Jets finalised their preparation for round one with an intra-club hit-out on Thursday night after beating Leeton-Whitton by about 11 goals in their only trial game last week.

The Jets face TRYC in a grand final rematch in round one.