Seven months after the Demons pulled the pin on their attempts to partner him with Gawn, Grundy will line up at the SCG on Thursday night as the Swans' No.1 ruck for their opening-round blockbuster.
The move came after the two-time All-Australian was initially squeezed out of Collingwood in 2022 because of salary cap pressure.
Grundy has so-far impressed at his third AFL club in three years, shining in last week's practice match against the Brisbane Lions.
Brodie Grundy's pre-season form for Sydney has been impressive. (Dan Himbrechts/AAP PHOTOS)
Asked whether he believes Grundy will have an axe to grind at their reunion, Gawn was candid.
"I presume he will," Gawn said on Wednesday.
"Anyone who's gone out of two teams now and found a new place and won a chance to play (the) first game of the year against your old team, I feel like that might be a bit of the thought process going into the game.
"But he doesn't need to prove anything to me and I dare say he doesn't need to prove a thing to his teammates or the AFL community. He seems happy."
Recruited by Melbourne to work in tandem with Gawn, Grundy was ultimately dropped and missed out on a finals appearance last year after the Dees found they functioned better with Gawn as the sole ruckman.
Still, the Melbourne skipper expects a tough battle ahead when he goes head-to-head with his former teammate.
"There might be a stalemate in the end because we know each other's strengths and weaknesses quite well," Gawn said.
"I'm sure there's going to be moments where we're going to see Brodie at his best and hopefully, they're just moments.
"I wouldn't mind him being best-on-ground but us winning by 20 or 30 points."
Grundy will not be the only Swan having a Thursday night reunion.
Former Demons midfielder James Jordon will make his debut in the red and white after impressing in the pre-season.
Moving interstate after failing to land a permanent spot in Simon Goodwin's best 22, the unused 2021 premiership substitute starred in the trial game against the Lions.
Sydney stalwart Dane Rampe said the 23-year-old has "made a difference" since arriving in the harbour city.
"He's probably snuck under the radar. He couldn't have impressed any more," Rampe said.
"Nothing seems to faze him. He's provided a great bit of depth and probably a little bit of experience as well.
"You can get stuck in your ways and that's why we embrace having Brodie and James come in because they offer a different perspective."
In the biggest selection news, Melbourne named star midfielder Clayton Oliver despite his turbulent pre-season in which he took time off for personal leave amidst his off-field troubles.
The Demons also named Charlie Spargo, who wasn't able to play pre-season due to an Achilles tendon issue.
Forward Josh Schache was selected ahead of Tom McDonald, while Jack Billings, Caleb Windsor and Blake Howes will all play their first games for Melbourne.
Sydney enter the match without injured trio Callum Mills, Luke Parker and Taylor Adams.
