Manson won three titles or "red coats" overall with the Central Regional Performance Centre. He also triumphed in the premier double and quadruple sculls.
Drysdale was understood to be suffering from a sore neck after a busy weekend of racing in which he finished second in the premier coxless four, and third in the pair.
He has yet to comment after the single sculls final, but told the Herald on Sunday last week he was happy with how the selection procedure will play out.
"We tend to select our crews early in March, and while that can work in some cases, in others it can be held open.
"Rowing New Zealand have decided early in the cycle they will give us both time, and I think that works pretty well.
"Not having to peak at this time of year is a positive. Being quick a few weeks out from a world champs is a lot easier than doing it now and going back to do it again. We're at the selectors' discretion. This is obviously a big shift in their thinking, but a progressive one."
One priority for Drysdale is dropping weight. He started at "a daunting prospect" of around 120kg, has removed 14kg but wants to shed about 5kg more to get to an optimum 101-102kg.
Manson's also satisfied with how the year will play out.
"The best way to pick a single [sculler] is to see who is fastest over 2km on the water. Whether they do it now or through trials at World Cups, it doesn't make much difference to me.
"The fastest person should be there, so I want to make sure it's me. I guess if it was now it'd be in my favour, but [the process] gives Mahe a little longer to see if he can get back to where he's been."
"[However] I've done the least amount of training I ever have over summer. I feel like I've got a lot more to improve. He'll get faster, but I will too. May the best man win."
Manson looks the favourite if early season form is a gauge. He also beat Drysdale at the Christmas regatta and North Island club championships. The 28-year-old won both his World Cups last year –overtaking Drysdale's world-best time in the process at Poznan - but finished fifth at the world championships as he battled injury.
Drysdale is returning after a year off following his Games triumph by less than the width of a bow ball in Rio. The 39-year-old's pedigree is undisputed as a double Olympic and five-time world champion. He is training under Calvin Ferguson – his coach from 2007 and 2008 – after the departure of former mentor Dick Tonks from Rowing New Zealand's stable.
