St Kilda have been urged to look toward adding reinforcements to their tall defensive stocks and inside midfield depth through the upcoming off-season.

The Saints are anticipated to be one of the more active clubs in the trade and free agency space in 2023 as part of Ross Lyon's first exchange window in charge of the club since making his return to Linton Street.

While Lyon and list management leaders Stephen Silvagni and Graeme Allan are understood to be building a list of trade targets for the upcoming off-season, the Saints also have a plethora of players unsigned beyond this year.

Saints CEO Simon Lethlean explained earlier this week that the handful of off-contract players will give the club some flexibility in their list planning for 2024, with gaps in their group likely to open up further as they get a better understanding of their squad through the remaining rounds of 2023.

The Saints have suffered three losses in their past four matches as they look to hold onto a top-eight spot under Lyon, with weaknesses beginning to show throughout multiple lines of the currently sixth-placed side.

After conceding more than 60 points in a game just twice through the opening six rounds, the Saints have allowed their opposition to score an average of 88.2 in their past six matches.

MELBOURNE, AUSTRALIA - FEBRUARY 01: Head of Talent and Acquisition, Graeme Allan and List Manager Stephen Silvagni look on during a St Kilda Saints AFL training session at RSEA Park on February 01, 2023 in Melbourne, Australia. (Photo by Darrian Traynor/Getty Images)

The concerns have led Collingwood great Nathan Buckley to believe the Saints should be looking toward adding an intercept defender come the off-season, potentially strengthening their current rearguard talls of Callum Wilkie, Josh Battle and Dougal Howard.

The former Magpies coach told Fox Footy that Lyon's crew would likely benefit from a fresh face down back, along with another inside midfielder to help their contested and clearance efforts.

"I think (St Kilda) want another intercept defender to support your team defence," Buckley said in the wake of St Kilda's 28-point loss to Brisbane on Friday night.

"You've got the tall forwards up forward, you want a good run with your front six mix.

"Maybe (St Kilda would want) another inside bull, a contested ball winner, a clearance player (to go with) a key defender.

"I think that's what you're looking for."

The AFL's player movement landscape in 2023 is set to see a bevy of key defenders present as the leading names potentially up for grabs, with restricted free agent trio Ben McKay, Harry Himmelberg and Tom Doedee among those likely to gain external suitors.

Geelong's Esava Ratugolea is understood to be of interest to Port Adelaide this year, with the South Australian club also reportedly keeping an eye on McKay.

Tom Doedee during the AFL match between Essendon and Adelaide, Round 4, 2022 (Photo by Cameron Grimes / Zero Digital Media

The Saints have a restricted free agent of their own to deal with among their extensive list of unsigned names, with midfield-forward Jade Gresham weighing up his future for next year.

Both Carlton and Hawthorn have been tied to the South Morang junior, with Buckley believing the Saints should be working to retain their 2018 leading goalkicker, but only if all parties buy into the same goal.

"You're keeping Jade Gresham," Buckley said of St Kilda's ideal list plans.

"There's not many players like him that can win the ball through the midfield and then go and finish forward.

"Jade has got to buy into the club as much as the club is going to buy into him."

While the Blues are believed to be showing interest in Gresham, St Kilda's have been heavily linked to Carlton tall Tom De Koning.

The emerging ruck-forward is said to have suitors in Geelong, Sydney and Essendon along with the Saints this year, while Carlton will press hard to retain their off-contract talent.