Since his fifth place in the B final of the double sculls in Rio with his Whanganui partner Chris Harris, the 27-year-old Manson has stepped into the vacancy in New Zealand's single scull boat and prospered at the 2017 World Cup events.
Manson blitzed the single scull fields in both Poland and Switzerland, and became the fastest man in the sport when he beat Drysdale's unofficial world record time - as rowing does not keep official records due to the different conditions at their regattas.
Ten years his senior, Drysdale will be looking to make a statement on the Whanganui River this November as both he and Manson will begin their rivalry to see who gets the New Zealand boat seat for 2018.
When the organisers of the Billy Webb Challenge switched from biennial to a yearly format in 2015, it was with the belief that every second year would still be the major event with more of a festival focus in the alternate year - given 2015 trialled the Armada Cup format.
However, the announcement of Drysdale v Manson plus the prospect of more international scullers and the current national squad members to come means the Whanganui Rowing Association is pulling out all the stops.
"The rowing gods couldn't have written a better script for this year's race," said association spokeswoman and district councillor Philippa Baker-Hogan.
"And with further high profile athletes plus members of NZ Rowing's Elite Summer Squad to add to the spectacle, this event is set to once again deliver the best of the best on the world rowing stage to the banks of the Whanganui River."
Based in Lake Karapiro, Drysdale considers Whanganui his home away from home.
"I always enjoy racing in Whanganui, it is a beautiful river and town.
"Whanganui has a very proud history in rowing, hosting New Zealand's first World Championship win in 1908 and producing many of our country's best."
The Challenge is iconic and a great opportunity for the elite rowers to support their provincial communities, Drysdale added.
"It is a unique event where any rower can enter and compete against the best rowers in the world.
"I am proud to have raced in every Billy Webb since its inception in 2008 and look forward to being back again in November."
Manson, who is currently nursing sore ribs, has departed for the 2017 World Rowing Championships in Sarasota, Florida, USA, and is also looking ahead to November.
"Mahe has been a great inspiration and support to me, but the thought of taking him on in the historic 5km Billy Webb Challenge - where Billy Webb won the world title nearly 110 years ago - is very special and will be a great early season shakedown for Mahe and myself."
The race will be on Sunday, November 26.
Support events include the annual Jury Cup Regatta, which will be held on the Aramoho 2000m course the day before.
Also being held on the Sunday are the Secondary School Sprint Regatta Challenge and the newly named Community Eight's race.
Further details can be found online at www.billywebbchallenge.co.nz