"I've won every race this summer and I've won every race ... that we've lined up against between myself and Mahe. So yeah I feel like I'm going really well and improving all of the time and learning a lot from each race. I feel like I'm in a really good place."
Despite his recent dominance over Drysdale, there are still questions over whether the more inexperienced Manson will get the nod from Rowing NZ selectors.
Rowing NZ High Performance coach Mike Rodger told Radio Sport the decision on who will take the single sculls seat is still "a little bit grey".
"I think we want to win medals at the Olympics and we've got to make sure that we're getting that right and putting the right person into that position," he said. "It is a little bit grey and it has allowed for a little bit of questions to be asked about it.
"It's always going to be hard to put the person out of the boat that wins the race or the trial race. So I think Robbie has done no harm there."
One factor against Manson could be his disappointing performances at the last two world championships, where he finished in fifth both times he held the seat.
"[Previous performance] is definitely one of the questions Rowing New Zealand has to ask around world champs and making sure the person [can perform]," said Rodger.
"We know Mahe can do it, we know he can almost be back in the field coming into certain regattas but he has had that ability in the past to be able to get it right at the right end of the world champs or the Olympics.
"[But] I do think it would be hard for Robbie not to come away with the spot."
The final decision on who will get the nod to compete at this year's World Cups and world championships will be announced on Thursday.