They played side-by-side on the A-League's biggest stage, but Bulli midfielder Dean Heffernan isn't planning on paying former teammate and Dapto-Dandaloo player-coach Noel Spencer any favours when the pair meet on Sunday.

The former A-League duo will face-off at opposite sides of the Illawarra Premier League decider at WIN Stadium, which will potentially bring to a close two illustrious careers.

Spencer has already made the decision to hang up the boots at season's end while Heffernan's playing future will come under the microscope after the grand final stoush.

Both had extensive careers in the A-League and the old NSL and teamed up for Central Coast Mariners in their 2006 1-0 grand final loss to Sydney FC.

Heffernan, who was later sent off in Perth Glory's 2012 grand final defeat, described his former teammate as "one of the best captains" he has ever played under, but admits any history will be cast aside on Illawarra football's grand final day.

"He is a good bloke and a good player, but he is not going to get a present this week," Heffernan said.

"Maybe if I see him out I can buy him a beer or something."

While it mightn't have the same prestige as an A-League decider, Heffernan was adamant he'd be taking things just as seriously come kick-off.

"A grand final is a grand final. There is no easy way to get to a grand final let alone win the league, so this one will be rated up there with all the other grand finals," Heffernan said.

Many will be expecting the former A-League defender to play a starring role on Sunday.

But with an impressive young squad by his side, Heffernan was confident the entire League Championship-winning side would be ready for the rigours of a grand final stoush.

"The thing is with these boys, they love the big occasion and they love the big games," Heffernan said.

"There are a lot of young players and really good players. I have been so impressed with all of them. Their attitude and things like that. I think all these boys will be well up for it to play on WIN Stadium in front of a decent crowd.

"There are so many people who put a tireless amount of effort every weekend and every week for us boys to only have to worry about training.

"All we can do is repay all that on the pitch."