The veteran coach has admitted that he could end his third stint in charge of the Bavarians at the end of this season, when his existing deal expires
The 67-year-old took over the reins at the Allianz Arena in 2011 after Louis van Gaal's exit, and led the club to a Champions League final in May, only to see his side lose to Chelsea.
However, he has now admitted that his age means that he will most likely leave the club in 2013, with the board set to look for a younger option.
"Let's be honest, I have a two-year contract which ends on June 30 2012," he explained to Suddeutsche Zeitung. "And then another stage of life comes to an end. I am no longer 37 years old.
"Ultimately, it's also whether they want a young or an old coach here. At Bayern one thing is important: success."
Several names have been linked with the job, and it was revealed in June that the Bavarians had already made an approach for former Barcelona boss Pep Guardiola.
Lucien Favre, who led Borussia Monchengladbach to a fourth-placed Bundesliga finish last season, has reportedly been a long-term target for the club, but signed a new contract with his current employers in July.
Meanwhile, Bayern legend Franz Beckenbauer has admitted that he expects his former side to make a move for 38-year-old coach Thomas Tuchel.
"I imagine that [president Uli] Hoeness would consider him," he commented to Sport1.
Heynckes, who has had two previous stints with Bayern has also coached the likes of Real Madrid, Schalke and Borussia Monchengladbach.