Ryan notched 125 games for West Coast and produced a memorable soaring mark in the passage of play that sealed the club's thrilling 2018 grand final win over Collingwood.
The 29-year-old's knack for taking spectacular marks earned him the nickname "Flyin' Ryan'', and West Coast fans were sad to see him go when he sought a trade to St Kilda at the end of last season.
Ryan has enjoyed a consistent start to his life at St Kilda, kicking 8.9 across six games to establish himself as an important part of their forward-line mix.
The creative goalsneak looms as a key figure in Sunday's match against his former side.
"Yeah, Flyin' is so well loved within our football club," Eagles coach Andrew McQualter said.
"He's a premiership player and he's great person, but he's now in the opposition and it won't be any different.
"Knowing Liam, he'll probably have a laugh and a joke with a few players out the field, but it will also be competitive.
"He'll be trying to win for his team, and we'll be trying to stop him as much as we can."
Star Eagles midfielder Elliot Yeo has already joked he won't want to be anywhere near Ryan when a high kick goes up, out of fear of being jumped on for a mark-of-the-year contender.
"My guess is Liam will fly for a few hangers this week," McQualter said.
"That's just what he does, but our job would be trying to stop him from kicking goals and helping their team."
St Kilda are struggling at 2-4 despite their high-profile off-season trade bonanza that netted them Ryan, Tom De Koning, Jack Silvagni and Sam Flanders.
The Saints have beaten GWS and Port Adelaide this season, and came close against Collingwood (12 points) and Adelaide (one point).
St Kilda were the only team to lose to West Coast last season, and there is huge pressure on them to avoid another slip-up.
Saints coach Ross Lyon coached McQualter between 2007 and 2011 at St Kilda, and knows how dangerous the Eagles can be on their day.
"They've had some really good wins, some great spirit, and they're building," Lyon said.
"They're really well coached by 'Mini' McQualter, one of our favourites here."
The Eagles (2-4) recalled Malakai Champion, forward Jack Williams and utility Ryan Maric, while the Saints included Dougal Howard and Anthony Caminiti.
17°C