Drysdale won his second Games gold by less than the width of bow ball over Croatian Damir Martin at Rio, becoming New Zealand's oldest Olympic champion at 37 years, eight months and 25 days. He was also the country's oldest gold medal winner in London.
If he won in Tokyo, Drysdale would take over from Brit Harry Blackstaffe's record as the Games' oldest single sculling champion... at London in 1908.
Negotiations would also be required if he wants to continue with coach Dick Tonks, who parted ways with Rowing New Zealand during the Rio campaign.
However, rowing produces its share of exceptional older athletes. At 38, Brit Sir Steven Redgrave won gold in the coxless four at Sydney, compatriot Greg Searle earned bronze in the eight at London aged 40, and Norwegian Olaf Tufte - a former single sculls rival of Drysdale - was also 40 when he took bronze in the double sculls at Rio.
The difference is Drysdale would be on his own and must regain the single sculling spot from incumbent Robbie Manson at trials over the next three years.
Manson finished fifth at this year's world championship but had been hampered by injuries after overtaking Drysdale's world-best time at Poznan in June.
Fans could be treated to a trial similar to that of Drysdale versus Sydney Olympic champion Rob Waddell in 2008.
Drysdale's biggest asset is an instinctive ability to conquer adversity.
A water skier drove into him on Lake Karapiro and cracked two vertebrae in his spine before his maiden world championship in 2005.
At the 2008 Beijing Olympics, an illness leading in meant he had expended his energy with 200m to go and couldn't maintain his lead. He admitted to no memory of the final strokes to secure a bronze, after which he collapsed in the boat and was stretchered away.
A belated return in 2013 saw him ousted from the world championship quarter-finals. A fractured rib from a bike crash hindered preparation after a post-Olympic sabbatical.
Drysdale wrote an email at 4.30am the following day, describing the impact of missing the world championship podium for the first time since transferring to the single sculls in 2005.
The upshot was this summary: "I expect to be back on the podium in Amsterdam next year and pushing for gold again in three years [at the Olympics]."
He was as good as his word.
Drysdale took 10 months off after his Rio gold, returning to training with the national summer squad at Lake Karapiro on Tuesday.
"I back myself to take it up another level," he told Radio Sport.
"Tokyo is the reason I'm back. To make it there I first need to get my spot back in the team and hopefully I can do that in the next four months. If I can do that, I'm going to be pretty competitive on the world stage."
Drysdale has fashioned a crème de la crème Olympic career and can achieve little more in the sport, yet he wants to continue building his legacy.
"I have to decide whether winning another Olympic gold would be as good as the first and whether I have the passion," he said in the aftermath of the London Games.
Five years on, the dream of another Olympic gold hanging around his neck remains too addictive to ignore.
