With Jake already selected in the team for Moscow in the 10,000m, the 23-year-old Hamilton twins, now based in Kenya and Ethiopia, will wait to see if the selectors add Zane to the nine-strong New Zealand team.
Meanwhile, it appears shot putter Tom Walsh's hopes of making the world champs are over, finishing short of the required B selection standard of 20.10m at his last opportunity in Madrid, Spain, yesterday.
Walsh's best throw at the Madrid meeting was 18.53m.
Pole vaulter Eliza McCartney provided the best New Zealand performance of the World Youth Champs in Donets, Ukraine, placing fourth in the final, clearing 4.05m.
The Auckland 16-year-old cleared 4.05m on her second attempt, just missing third place on the countback, before having three attempts at 4.15m, which would have improved her New Zealand record of 4.11m.
McCartney went into the final ranked eighth but beat several athletes with personal bests over 4.30m in the final. The event was won at 4.
The medley relay team finished with the 10th-fastest time in the qualifying round, narrowly missing the finals this morning.