The pursuit of Olympic gold could see shot putter Val Adams call time on her season this week.
A decision is pending, but Adams' inability to throw beyond 19m in competition means a tilt at a fifth consecutive world championship on August 22 in Beijing is unlikely.
Attempting to become New Zealand's first Olympian to win a gold medal at three consecutive Games in Rio next year looks a more logical goal.
Among Kiwis, only Adams, runner Peter Snell, rowers Dick Joyce, Caroline and Georgina Evers-Swindell, coxswain Simon Dickie, kayakers Ian Ferguson and Paul MacDonald and equestrian rider Mark Todd have won golds at consecutive Olympics.
Adams has spent the season rebuilding after undergoing surgery to her right elbow and left shoulder last year.
She returned with a throw of 18.79m to finish fifth at the Diamond League in Paris on July 4, a performance which ended her run of 56 consecutive victories from August 2010. Adams has since thrown 18.73m (first in a weakened Lucerne field), 18.59m (second in London) and 18.69m (fourth in Stockholm).
She is understood to have thrown more than 19m regularly in practice but cannot translate that form to competition.
If Adams pulls out of the world championships, she is likely to return home from her Switzerland base this month.
Her manager, Nick Cowan, told the Herald Adams' season was "up for review" because she was reluctant to throw if not 100 per cent. He said her return to top flight competition had been "more challenging than was anticipated".
German Christina Schwanitz is the new alpha female in the discipline. She set a personal best of 20.77m in May.
Adams has not thrown beyond that mark since beating Schwanitz with a throw of 20.88m at the 2013 world championships. Schwanitz has now thrown more than 20m in her last six competitions. China's Lijiao Gong and American Michelle Carter have also surpassed 20m this season.
Last year, Adams' dominance saw her become the first female thrower to be awarded the IAAF world governing body's athlete of the year. She set eight of the 10 best throws in 2013 and 2014.