But Napier Girls' High School athletics and harriers coaching legend Sheila Smidt believes it is not impossible, saying her former student may not yet have realised "how good she is".
The weekend's race comes after the season's one blip when Manning ran 2m 7.09s in the rain at the Australian national championships in Sydney last Thursday and missed a place in the final at what was one of New Zealand's most successful track and field meetings overseas in recent years.
It was particularly so for female athletes, with Taranaki sprinter Zoe Hobbs winning the 100 metres, 22-year-old former Havelock North High School athlete Georgia Hulls the 200 metres in a wind-legal PB of 23.17s, North Harbour athlete Isabel Neal the 400 metres, and Hobbs, Hulls, Livvy Wilson (North Harbour) and Rose Elliott (Canterbury) the 4x100 metres women's relay in a New Zealand record 44.05s.
Hulls will also run the 200 metres in Brisbane, for which the forecast on Saturday also is not the best, with showers expected during the day and south-southwest winds up to 30km/h but easing in the evening.
It was an anxious wait for Manning after lodging her entry for the race, but not knowing until Tuesday whether she had made the field.
She said had she not been included it would have been "done" for the season with no other alternatives and she'd return home.
She's hopeful of another PB in the right conditions, saying that her Sydney heat was tough, very strategic and, along with the rest of the trip, "a big learning curve".
"This trip has been quite stressful with Covid and things I didn't anticipate to be quite so hard, so I think that was part of the reason I didn't do so well on Thursday (last week)," she said.
She arrived in Brisbane on Thursday, taking the advice of her coach to "recover like crazy," but take in "a run and then a few pick up things tomorrow [Friday]… but easy".
To make the top 10 in the New Zealand all-time list in the event, she will have to go just 0.03sec quicker than the 800m PB of former national 1500m champion and Olympic Games runner Christine Pfitzinger, and 0.14sec quicker to beat the best of Anne Audain, one of New Zealand's greatest track athletes who ran the heats of the 1976 Olympic Games 800m and 1500m and went on to win the 3000m gold medal at the 1982 Commonwealth Games in Brisbane and races at various distances up to the 42km of the marathon.
Meanwhile, it's an anxious wait for several other Hawke's Bay athletes with teams for the World Junior Championships in Colombia in August and the Oceania Games in Brisbane in November being named this week.
Among them is 17-year-old Hastings runner Karsen Vesty who, in a solo time trial in Hastings a fortnight ago, ran a qualifying 1500 metres in 3m 48.26s.
It was more than six seconds quicker than the PB he ran in winning the national Under 18 title on the same track on March 4. He is, however, just the third-fastest of a trio of teenagers who have run qualifying times, and no more than two can go to the world event.
