Bailey, 26, has played just 41 games in a career blighted by injury, but has managed a career-high 17 matches this season, including last Friday night's qualifying final win over the Sydney Swans.
Bailey's ability to shoulder most of the Hawks' ruck load this year has released Jarryd Roughead and David Hale to spend more time in attack, with Roughead taking his game to another level on his way to the Coleman Medal.
"Max is not going anywhere, he's Hawthorn through and through," Casley told AFL.com.au on Thursday.
"We'll sit down with the club at the end of the year and work something out."
Recent reports have linked Hawthorn with 20-year-old Brisbane Lions ruckman Billy Longer, but Casley is confident that does not cloud Bailey's future with the Hawks.
"When Max has been fit and up and running this year he's been the Hawks' No. 1 ruckman," Casley said.
"He obviously hasn't been able to play every game this year and clubs need to make sure they have some back-up."
That Bailey is still playing is a credit to his perseverance and the Hawks' faith in the No. 18 pick in the 2005 national draft.
Three knee reconstructions limited Bailey to just six games in his first five seasons at Hawthorn. After coming back to play 16 games in 2011, a wrist injury on the eve of last season limited him to just two games.
Bailey is one of five Hawk free agents yet to re-sign with the club.
Restricted free agent Lance Franklin's future has been a source of fascination for footy fans since he put off contract talks with the Hawks in February.
Franklin has stuck to his decision not to re-open negotiations with Hawthorn until the end of the season, when he will also have to weigh up an offer from Greater Western Sydney reported to be up to $9 million over six seasons. Franklin could also boost those earnings through an AFL ambassadorial role.
The Hawks' other free agents are Xavier Ellis, Brent Guerra and Michael Osborne (all unrestricted).
Hawthorn faces tough decisions on the futures of Ellis, 25, who has played just two games in a 2013 season decimated by injury, and Guerra, 31.
Osborne, 31, is likely to retire.