"I'm starting to get some glimpses of the old speed I've had, and overall I'm pleased to be back competing with the rest of the world.
"I'm disappointed not to get the spot, but Robbie raced really well and was clearly in great form.
"I'm happy working towards my long-term goal [of the Tokyo Olympics], but now need to change my plan for the next six to seven weeks.
Drysdale said he would have liked to have found last weekend's speed four to six weeks ago.
"I thought a year was plenty of time [to get back up to speed] but it's been frustrating and taken more time than I wanted.
"In the bigger scheme of things, I've still got two years."
By the end of the week Rowing New Zealand's expected to confirm what crews are going to the world championships and those they want to reassess.
"If I can strengthen another boat, I'm available," Drysdale said.
"As soon as the worlds are over, I'll be back in the single aiming for next year's selection but I know not every boat will be open for selection.
"Both Robbie and I were aware that whoever missed out, would take what we're given."
In premier level events, Drysdale finished third in the coxless pair and second in the coxless four at the national championships in February.
The 39-year-old hopes the same selection process, where he and Manson were given to the final World Cup of the international season to prove themselves, is also used next year.
He insists it doesn't jeopardise a world championship or Olympic campaign.
"I quite liked where it was flagged a long way in advance and we were both clear of the criteria, so we'll see what Rowing New Zealand think.
"I think it's better than having to be at your utmost in March.
"I'd rather be heading that way now, with six to seven weeks to go."