The 23-year-old has spent the last two seasons at St Andrew's, with the first of those being on loan from Manchester United, although last summer he made the permanent switch to the Second City.
After putting pen to paper on a four-year contract at Birmingham in August 2022, Chong went on to play 38 second-tier matches for John Eustace's men last term, scoring four goals and assisting on five occasions.
Following his £1.5m move to Blues almost a year ago, the Dutchman still has three years left on his current terms at the club, meaning the West Midlands outfit are in a good position to drive a hard bargain with potential suitors.
One possible destination for Chong - according to the Daily Mail - is Luton, and Birmingham are said to be willing to offload the winger in this window if they receive £5m for the player.
The Hatters have first-hand experience of the former United man's ability, with Chong causing headaches for the hosts at Kenilworth Road in August 2021 when Lee Bowyer's Blues picked up a 5-0 win.
Rob Edwards will navigate Luton through their first top-flight campaign since the 1991-92 term after they dramatically earned promotion with a playoff-final win against Coventry City at Wembley in May.
Having already secured the services of Rotherham United forward Chiedozie Ogbene, it is understood that Luton are once again looking to the Championship for potential incomings, with Birmingham's Chong being high on their list of targets.
Mads Andersen has also arrived at Kenilworth Road ahead of the Premier League season from League One side Barnsley - an incoming which has complemented some key contract extensions.
Both captain Tom Lockyer and Pelly Ruddock Mpanzu have signed fresh terms at the top-flight newcomers, with the duo being large parts of Luton's success in the 2022-23 campaign.
Edwards's men are also said to be looking to bolster their goalkeeping ranks, having seen multiple bids for Blackburn Rovers stopper Thomas Kaminski rejected, with the Lancashire hoping to pocket up to £4m for the Belgium international.
Such interest in the 30-year-old has been caused by Ethan Horvath's loan spell with the Hatters coming to an end, meaning the American will be put through his pre-season paces by parent club Nottingham Forest.
The possible sale of Chong will be a huge blow to Birmingham's aims to improve on their 17th-placed finish in the Championship last term, however the club have brought in attackers Tyler Roberts and Koji Miyoshi to strengthen Eustace's offensive options.
The Dutchman could be the second high-profile departure from St Andrew's this summer, after 17-year-old Jobe Bellingham moved to second-tier rivals Sunderland for around £3m.