A best-and-fairest winner at GWS, Haynes has become a crucial member of the Blues' defence and has been excellent in their incredible resurgence under interim coach Josh Fraser.
The 34-year-old is realistic the end is close, after being part of the Giants' inaugural season in 2012, but is yet to decide what he will do beyond 2026.
Since leaving GWS as an unrestricted free agent at the end of 2024, Haynes has signed two one-year contracts.
"We'll see at the end of the year, but the body's feeling pretty good - it's felt worse over my career, so that's a plus," Haynes told AAP.
"I'm just enjoying my footy, and we've got a great amount of experience and youth in the team, and I'm really enjoying playing with them.
"The exuberance helps me having fun playing footy again, so yeah, we'll see what happens at the end of the year."
Carlton will be a gunning for an extraordinary eighth straight win when they face Hawthorn at the MCG on Saturday night.
After conceding 100 points or more in six of their first nine games this year under former coach Michael Voss, the Blues have given up an average of just 67.4 points in their current 7-0 run.
The highest score Carlton have conceded under Fraser is 84 points in a rousing four-point upset of Geelong in round 12.
The Blues' defence has stood tall, even in the absence of vice-captain Jacob Weitering for the past four matches.
Harry Dean has been a revelation, but the Rising Star contender joined Weitering on the sidelines for last Saturday night's gritty win over Richmond.
Dean will return from an unexplained cut on his hand to take on the Hawks.
"Over the pre-season, we built a real emphasis on defending as a back-six system, and we really knuckled that down," said Haynes, who is four games away from a 250th AFL appearance.
"(Assistant coach) Ash Hansen has done a great job with us backs playing the system footy.
"Anyone that comes into the team, if you're a first-year like Deany, or an old player like me, there's a system that we all trust, and we all play.
"The next guy stands up and comes in the team and plays his role."
13°C