Reid will undergo an operation on Tuesday to fix the Achilles tendon injury he sustained five minutes into Saturday's NEAFL game, his second match back from the quadriceps injury he suffered in round three.

Longmire had hoped Reid would be fit for Sunday's clash with North Melbourne, but he's now staring at six more weeks on the sideline.

McVeigh, meanwhile, underwent surgery on the weekend to repair the broken collarbone he suffered late in Thursday's 12-point loss to Geelong, and is expected to miss five weeks.

His best-case scenario would likely be the round 21 clash against Melbourne at the MCG, although that match would probably come too early for the 33-year-old, who Longmire expects will retire at the end of the season.

"At the moment he's moving his shoulder around pretty well, it's probably around a four to five weeker, six weeks if you're a bit conservative, four weeks if you're not so conservative so he's probably around that mark," Longmire said.

"He's in a positive mindset, he's moving his arm around pretty well, he's up and about today, those things happen in footy, and [he's] getting on with it."

McVeigh landed awkwardly on his right shoulder late in the fourth quarter against Geelong, in a game where midfielders Dan Hannebery (calf) and Kieren Jack (knee) also picked up injuries.

Hannebery is set to miss a month with a torn calf, while Jack's medial ligament injury isn't as bad as first thought.

And while Hannebery and Jack should recover to play a part towards the back end of the season, Reid's participation for the remainder of 2018 is in serious doubt given the luckless forward's recent run with injury.

Lewis Melican's season may also be over, with the defender also scheduled for surgery on Tuesday to repair the hamstring tendon he re-injured last weekend.

An eight-week recovery period is expected.

"We'll just get over the first hurdle which is them having the operation and see how they go after that," Longmire said. "We were hoping to have them back probably this week but that's not going to happen now so we've just got to make sure we do whatever we can now to make sure they get through their various operations tomorrow and hopefully get them up and running by the end of the season.

"It was an interesting nine days from our Richmond game through to our reserves game on the weekend, I think we lost eight senior players in the space of nine days.

"Things can change pretty quickly in this game and that's just part of the resilience you have to have, whether you're a player, whether you're a supporter, whether you're a staff member, whether you're a coach."

In better news for the Swans, Longmire was hopeful Isaac Heeney (concussion) and Tom Papley (hip) would be fit to line up against the Kangaroos.

Irishman Colin O'Riordan is also a strong chance of being called into the seniors for his first AFL game.

"He's a chance, he'd be a chance regardless of the injuries," Longmire said.

"He's been able to be consistent for quite a while. He works really hard on his game, he's a good two- way player, he's incredibly enthusiastic and he runs hard.

"He's a really popular team member in our reserves and he's in with a chance."